C-like emitter: Pass switch condition type to case emitter

In WGSL, the switch condition and case types must match.
https://www.w3.org/TR/WGSL/#switch-statement

The Slang WGSL emitter solves this by doing an explicit conversion.
For this reason, pass the switch condition type to the function that emits the cases.

Note that this type mismatch should eventually be fixed in the front-end,
as discussed in issue shader-slang#4921.
However, that is not yet done, so for now this helps to address issue shader-slang#4807.

source/slang/slang-emit-c-like.cpp

@@ -3200,7 +3200,7 @@ void CLikeSourceEmitter::emitLayoutSemantics(IRInst* inst, char const* uniformSe
     emitLayoutSemanticsImpl(inst, uniformSemanticSpelling, EmitLayoutSemanticOption::kPostType);
 }
 
-void CLikeSourceEmitter::emitSwitchCaseSelectorsImpl(SwitchRegion::Case const*const currentCase, bool const isDefault)
+void CLikeSourceEmitter::emitSwitchCaseSelectorsImpl(IRBasicType *const /* switchCondition */, SwitchRegion::Case const*const currentCase, bool const isDefault)
 {
     for(auto caseVal : currentCase->values)
     {
@@ -3370,7 +3370,8 @@ void CLikeSourceEmitter::emitRegion(Region* inRegion)
                 for(auto currentCase : switchRegion->cases)
                 {
                     bool const isDefault {currentCase.Ptr() == defaultCase};
-                    emitSwitchCaseSelectors(currentCase.Ptr(), isDefault);
+                    IRBasicType *const switchConditionType {as<IRBasicType>(switchRegion->getCondition()->getDataType())};
+                    emitSwitchCaseSelectors(switchConditionType, currentCase.Ptr(), isDefault);
                     m_writer->indent();
                     m_writer->emit("{\n");
                     m_writer->indent();

source/slang/slang-emit-c-like.h

@@ -372,7 +372,7 @@ class CLikeSourceEmitter: public SourceEmitterBase
     void emitFuncHeader(IRFunc* func) { emitFuncHeaderImpl(func); }
     void emitSimpleFunc(IRFunc* func) { emitSimpleFuncImpl(func); }
 
-    void emitSwitchCaseSelectors(SwitchRegion::Case const*const currentCase, bool const isDefault) {emitSwitchCaseSelectorsImpl(currentCase, isDefault);}
+    void emitSwitchCaseSelectors(IRBasicType *const switchConditionType, SwitchRegion::Case const*const currentCase, bool const isDefault) {emitSwitchCaseSelectorsImpl(switchConditionType, currentCase, isDefault);}
 
     void emitParamType(IRType* type, String const& name) { emitParamTypeImpl(type, name); }
 
@@ -526,7 +526,7 @@ class CLikeSourceEmitter: public SourceEmitterBase
     virtual void emitLoopControlDecorationImpl(IRLoopControlDecoration* decl) { SLANG_UNUSED(decl); }
     virtual void emitIfDecorationsImpl(IRIfElse* ifInst) { SLANG_UNUSED(ifInst); }
     virtual void emitSwitchDecorationsImpl(IRSwitch* switchInst) { SLANG_UNUSED(switchInst); }
-    virtual void emitSwitchCaseSelectorsImpl(SwitchRegion::Case const*const currentCase, bool const isDefault);
+    virtual void emitSwitchCaseSelectorsImpl(IRBasicType *const switchConditionType, SwitchRegion::Case const*const currentCase, bool const isDefault);
 
     virtual void emitFuncDecorationImpl(IRDecoration* decoration) { SLANG_UNUSED(decoration); }
     virtual void emitLivenessImpl(IRInst* inst);