Use ankerl/unordered_dense as a hashmap implementation (#3036)

* Correct namespace for getClockFrequency

* missing const

* Add missing assignment operator

* Remove unused variables

* Return correct modified variable

* Use stable hash code for file system identity

* terse static_assert

* Structured binding for map iteration

* Make (==) and getHashCode const on many structs

* Add ConstIterator for LinkedList

* Replace uses of ItemProxy::getValue with Dictionary::at

* Extract list of loads from gradientsMap before updating it

* Const correctness in type layout

* Add unordered_dense hashmap submodule

* Use wyhash or getHashCode in slang-hash.h

* refactor slang-hash.h

* Use ankerl/unordered_dense as a hashmap implementation

Notable changes:
- The subscript operator returns a reference directly to the value,
  rather than a lazy ItemProxy (pair of dict pointer and key)

slang-profile time (95% over 10 runs):

- Before: 6.3913906 (±0.0746)
- After:  5.9276123 (±0.0964)

* 64 bit hash for strings

So they have the same hash as char buffers with the same contents

* Narrowing warnings for gcc to match msvc

* revert back to c++17

* Correct c++ version for msvc

* Use path to unordered_dense which keeps tests happy

* Do not assign to and read from map in same expression

* Remove redundant map operations in primal-hoist

* Split out stable hash functions into slang-stable-hash.h

* 64 bit hash by default

* regenerate vs projects

* Correct return type from HashSetBase::getCount()

* correct width for call to Dictionary::reserve

* Use stable hash for obfuscated module ids

* Signed int for reserve

* clearer variable naming

* Parameterize Dictionary on hash and equality functors

* Allow heterogenous lookup for Dictionary

* missing const

* Use set over operator[] in some places

* Remove unused function

* s/at/getValue

3 files changed, 8 insertions, 7 deletions

diff --git a/tools/gfx/debug-layer/debug-shader-object.h b/tools/gfx/debug-layer/debug-shader-object.h
index 9f368a2c1..b5a268892 100644
--- a/tools/gfx/debug-layer/debug-shader-object.h
+++ b/tools/gfx/debug-layer/debug-shader-object.h
@@ -12,13 +12,13 @@ namespace debug
 struct ShaderOffsetKey
 {
     ShaderOffset offset;
-    bool operator==(ShaderOffsetKey other)
+    bool operator==(ShaderOffsetKey other) const
     {
         return offset.bindingArrayIndex == other.offset.bindingArrayIndex &&
             offset.bindingRangeIndex == other.offset.bindingRangeIndex &&
             offset.uniformOffset == other.offset.uniformOffset;
     }
-    Slang::HashCode getHashCode()
+    Slang::HashCode getHashCode() const
     {
         return Slang::combineHash(
             (Slang::HashCode)offset.uniformOffset,
diff --git a/tools/gfx/renderer-shared.cpp b/tools/gfx/renderer-shared.cpp
index 99188233a..1e4cbb2f4 100644
--- a/tools/gfx/renderer-shared.cpp
+++ b/tools/gfx/renderer-shared.cpp
@@ -3,6 +3,7 @@
 #include "core/slang-io.h"
 #include "core/slang-token-reader.h"
 
+#include "../../source/core/slang-stable-hash.h"
 #include "../../source/core/slang-file-system.h"
 
 #include "../../slang.h"
diff --git a/tools/gfx/renderer-shared.h b/tools/gfx/renderer-shared.h
index 38aa775be..32aa22b48 100644
--- a/tools/gfx/renderer-shared.h
+++ b/tools/gfx/renderer-shared.h
@@ -1043,7 +1043,7 @@ struct ComponentKey
     Slang::UnownedStringSlice typeName;
     Slang::ShortList<ShaderComponentID> specializationArgs;
     Slang::HashCode hash;
-    Slang::HashCode getHashCode()
+    Slang::HashCode getHashCode() const
     {
         return hash;
     }
@@ -1060,7 +1060,7 @@ struct PipelineKey
     PipelineStateBase* pipeline;
     Slang::ShortList<ShaderComponentID> specializationArgs;
     Slang::HashCode hash;
-    Slang::HashCode getHashCode()
+    Slang::HashCode getHashCode() const
     {
         return hash;
     }
@@ -1070,7 +1070,7 @@ struct PipelineKey
         for (auto& arg : specializationArgs)
             hash = Slang::combineHash(hash, arg);
     }
-    bool operator==(const PipelineKey& other)
+    bool operator==(const PipelineKey& other) const
     {
         if (pipeline != other.pipeline)
             return false;
@@ -1090,12 +1090,12 @@ struct OwningComponentKey
     Slang::String typeName;
     Slang::ShortList<ShaderComponentID> specializationArgs;
     Slang::HashCode hash;
-    Slang::HashCode getHashCode()
+    Slang::HashCode getHashCode() const
     {
         return hash;
     }
     template<typename KeyType>
-    bool operator==(const KeyType& other)
+    bool operator==(const KeyType& other) const
     {
         if (typeName != other.typeName)
             return false;