Implement default initializer list for C-Style type member (#7079)

* Implement default initializer list for C-Style type member

Close #6189.

Previsouly, for the C-Style member in a struct, if it doesn't have any initialize
expression, when we synthesize the ctor, we will not associate the
default value for the parameter corresponding to that member.

This bring some trouble that existing slang users has to add '= {}' to
every struct fields in order to make all the parameters in the synthesized ctor having
a default value, so people can still use `Struct a = {}` to create a
struct.

To make this use case convenience, we will automatically associated a
'= {}' as the default value for this case.

This PR also add support for empty initializing link-time sized vector/matrix by "= {}".
In addition, this PR also fix a bug in auto diff where we should not report error when proccessing
transpose on an empty struct.

2 files changed, 14 insertions, 12 deletions

diff --git a/tests/diagnostics/extension-full-name.slang.expected b/tests/diagnostics/extension-full-name.slang.expected
index 8001298c1..72eef77e3 100644
--- a/tests/diagnostics/extension-full-name.slang.expected
+++ b/tests/diagnostics/extension-full-name.slang.expected
@@ -1,39 +1,40 @@
 result code = -1
 standard error = {
-tests/diagnostics/extension-full-name.slang(184): error 30019: expected an expression of type 'GenericType<half>.State', got 'int'
+tests/diagnostics/extension-full-name.slang(185): error 30019: expected an expression of type 'GenericType<half>.State', got 'int'
     state1 = 0;    // Error: expected expr of type 'GenericType<half>.State', got 'int'
              ^
-tests/diagnostics/extension-full-name.slang(185): error 30019: expected an expression of type 'GenericType<float>.InnerType.Options', got 'int'
+tests/diagnostics/extension-full-name.slang(186): error 30019: expected an expression of type 'GenericType<float>.InnerType.Options', got 'int'
     options1 = 0;  // Error: expected expr of type 'GenericType<float>.InnerType.Options', got 'int'
                ^
-tests/diagnostics/extension-full-name.slang(186): error 30019: expected an expression of type 'NonGenericType.Config', got 'int'
+tests/diagnostics/extension-full-name.slang(187): error 30019: expected an expression of type 'NonGenericType.Config', got 'int'
     config1 = 0;   // Error: expected expr of type 'NonGenericType.Config', got 'int'
               ^
-tests/diagnostics/extension-full-name.slang(187): error 30019: expected an expression of type 'Container.Nested.Settings', got 'int'
+tests/diagnostics/extension-full-name.slang(188): error 30019: expected an expression of type 'Container.Nested.Settings', got 'int'
     settings1 = 0; // Error: expected expr of type 'Container.Nested.Settings', got 'int'
                 ^
-tests/diagnostics/extension-full-name.slang(188): error 30019: expected an expression of type 'Container.Nested.DeepNested.Record', got 'int'
+tests/diagnostics/extension-full-name.slang(189): error 30019: expected an expression of type 'Container.Nested.DeepNested.Record', got 'int'
     record1 = 0;   // Error: expected expr of type 'Container.Nested.DeepNested.Record', got 'int'
               ^
-tests/diagnostics/extension-full-name.slang(196): error 30027: 'getOptions' is not a member of 'GenericType<int>.InnerType'.
+tests/diagnostics/extension-full-name.slang(189): note: explicit conversion from 'int' to 'Container.Nested.DeepNested.Record' is possible
+tests/diagnostics/extension-full-name.slang(197): error 30027: 'getOptions' is not a member of 'GenericType<int>.InnerType'.
         intInner.getOptions(); // This won't compile as intInner doesn't have getOptions
                  ^~~~~~~~~~
-tests/diagnostics/extension-full-name.slang(226): error 30019: expected an expression of type 'GenericType<float>.InnerType.Options', got 'GenericType<half>.State'
+tests/diagnostics/extension-full-name.slang(227): error 30019: expected an expression of type 'GenericType<float>.InnerType.Options', got 'GenericType<half>.State'
             .createState(); // Error: expected expr of type 'GenericType<float>.InnerType.Options',
                         ^
-tests/diagnostics/extension-full-name.slang(228): error 30019: expected an expression of type 'GenericType<half>.State', got 'NonGenericType.Config'
+tests/diagnostics/extension-full-name.slang(229): error 30019: expected an expression of type 'GenericType<half>.State', got 'NonGenericType.Config'
     state1 = nonGenType.createConfig(); // Error: expected expr of type 'GenericType<half>.State',
                                     ^
-tests/diagnostics/extension-full-name.slang(230): error 30019: expected an expression of type 'NonGenericType.Config', got 'Container.Nested.Settings'
+tests/diagnostics/extension-full-name.slang(231): error 30019: expected an expression of type 'NonGenericType.Config', got 'Container.Nested.Settings'
     config1 = nested.createSettings();  // Error: expected expr of type 'NonGenericType.Config', got
                                    ^
-tests/diagnostics/extension-full-name.slang(304): error 30019: expected an expression of type 'Bar[3].DataStats', got 'int'
+tests/diagnostics/extension-full-name.slang(305): error 30019: expected an expression of type 'Bar[3].DataStats', got 'int'
     barStats = 0; // Error: expected expr of type 'Bar[3].DataStats', got 'int'
                ^
-tests/diagnostics/extension-full-name.slang(312): error 30019: expected an expression of type 'Bar[2].DataStats', got 'Bar[3].DataStats'
+tests/diagnostics/extension-full-name.slang(313): error 30019: expected an expression of type 'Bar[2].DataStats', got 'Bar[3].DataStats'
     bar2Stats = barArray.computeStats(); // Error: expected expr of type 'Bar[2].DataStats', got 'Bar[3].DataStats'
                                      ^
-tests/diagnostics/extension-full-name.slang(355): error 30019: expected an expression of type 'SimpleBase.NamedConfig', got 'int'
+tests/diagnostics/extension-full-name.slang(356): error 30019: expected an expression of type 'SimpleBase.NamedConfig', got 'int'
     config = 0; // Error: expected expr of type 'SimpleBase.NamedConfig', got 'int'
              ^
 }
diff --git a/tests/diagnostics/mismatching-types.slang.expected b/tests/diagnostics/mismatching-types.slang.expected
index a706e30e6..e247d16a8 100644
--- a/tests/diagnostics/mismatching-types.slang.expected
+++ b/tests/diagnostics/mismatching-types.slang.expected
@@ -20,6 +20,7 @@ tests/diagnostics/mismatching-types.slang(63): error 30019: expected an expressi
 tests/diagnostics/mismatching-types.slang(66): error 30019: expected an expression of type 'NonGenericOuter.GenericInner<int>', got 'int'
     c.i = 0;
           ^
+tests/diagnostics/mismatching-types.slang(66): note: explicit conversion from 'int' to 'NonGenericOuter.GenericInner<int>' is possible
 tests/diagnostics/mismatching-types.slang(68): error 30019: expected an expression of type 'NonGenericOuter.GenericInner<int>', got 'NonGenericOuter.GenericInner<float>'
     c.i = c.f;
             ^