Add -dump-module command to slangc (#6638)

* Add -dump-module command to slangc

The new -dump-module command to slangc will load and disassemble a slang module, similar to what would be seen by the -dump-ir command, except that -dump-ir tells slangc to print IR as it performs some compilation command. That is, -dump-ir requires
some larger compilation task.

-dump-module on the otherhand requires no additional goal and will simply load a module and print its IR to stdout independently from other compilation steps.

Its intended purpose is to inspect .slang-module files on disk.
It can also be used on .slang files which will be parsed and lowered
if slang does not find an associated ".slang-module" version of the
module on disk.

The compilation API is extended with a new IModule::disassemble()
method which retrieves the string representation of the dumped IR.

Closes #6599

* format code

* Use FileStream not FILE

* format code

---------

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>
Co-authored-by: Ellie Hermaszewska <ellieh@nvidia.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/tests/ir/dump-module.slang b/tests/ir/dump-module.slang
new file mode 100644
index 000000000..e22c3fca5
--- /dev/null
+++ b/tests/ir/dump-module.slang
@@ -0,0 +1,53 @@
+// This tests slangc's -dump-module command.
+// Dumping ".slang" should mean just that, and it should not automatically load up
+// a ".slang-module" when available, because the intent of the -dump-module command
+// is to see the file you requested. If there's a bug in slang-module output, it's
+// important that -dump-module looks at the specific file you requested.
+
+//TEST:COMPILE: tests/ir/dump-module.slang -o tests/ir/dump-module.slang-module -target spirv -embed-downstream-ir
+
+//TEST:SIMPLE(filecheck=CHECK1): -dump-module tests/ir/dump-module.slang-module
+//TEST:SIMPLE(filecheck=CHECK2): -dump-module tests/ir/dump-module.slang
+
+module "export-library-generics";
+
+public cbuffer Constants {
+    public float x;
+    public float y;
+}
+
+interface MyInterface
+{
+    int myMethod(int a);
+}
+
+struct MyType : MyInterface
+{
+    int myMethod(int a)
+    {
+        return a * 3;
+    }
+}
+
+int genericFunc<T: MyInterface>(T arg)
+{
+    return arg.myMethod(3);
+}
+
+public int normalFuncUsesGeneric(int a)
+{
+    MyType obj;
+    return genericFunc(obj);
+}
+
+public int normalFunc(int a, float b)
+{
+    return a - floor(b);
+}
+
+// CHECK1:EmbeddedDownstreamIR(6 : Int,
+// CHECK1:               OpCapability Linkage
+
+// CHECK2-NOT:EmbeddedDownstreamIR(6 : Int,
+// CHECK2-NOT:               OpCapability Linkage
+