NFC: Constify GenericTypeParamDeclGetValueTypeRequest's parameter

Author: hamishknight

include/swift/AST/TypeCheckRequests.h

@@ -5299,15 +5299,15 @@ SourceLoc extractNearestSourceLoc(RegexLiteralPatternFeatureKind kind);
 
 class GenericTypeParamDeclGetValueTypeRequest
     : public SimpleRequest<GenericTypeParamDeclGetValueTypeRequest,
-                           Type(GenericTypeParamDecl *decl),
+                           Type(const GenericTypeParamDecl *decl),
                            RequestFlags::Cached> {
 public:
   using SimpleRequest::SimpleRequest;
 
 private:
   friend SimpleRequest;
 
-  Type evaluate(Evaluator &evaluator, GenericTypeParamDecl *decl) const;
+  Type evaluate(Evaluator &evaluator, const GenericTypeParamDecl *decl) const;
 
 public:
   bool isCached() const { return true; }

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -626,7 +626,7 @@ SWIFT_REQUEST(TypeChecker, CustomDerivativesRequest,
               Cached, NoLocationInfo)
 
 SWIFT_REQUEST(TypeChecker, GenericTypeParamDeclGetValueTypeRequest,
-              Type(GenericTypeParamDecl *), Cached, NoLocationInfo)
+              Type(const GenericTypeParamDecl *), Cached, NoLocationInfo)
 
 SWIFT_REQUEST(TypeChecker, SemanticAvailableAttrRequest,
               std::optional<SemanticAvailableAttr>
@@ -643,4 +643,4 @@ SWIFT_REQUEST(TypeChecker, DefaultIsolationInSourceFileRequest,
 
 SWIFT_REQUEST(TypeChecker, ModuleHasTypeCheckerPerformanceHacksEnabledRequest,
               bool(const ModuleDecl *),
-              Cached, NoLocationInfo)
+              Cached, NoLocationInfo)

lib/AST/Decl.cpp

@@ -6122,8 +6122,8 @@ GenericTypeParamDecl *GenericTypeParamDecl::createImplicit(
 
 Type GenericTypeParamDecl::getValueType() const {
   return evaluateOrDefault(getASTContext().evaluator,
-    GenericTypeParamDeclGetValueTypeRequest{const_cast<GenericTypeParamDecl *>(this)},
-    Type());
+                           GenericTypeParamDeclGetValueTypeRequest{this},
+                           Type());
 }
 
 SourceRange GenericTypeParamDecl::getSourceRange() const {

lib/Sema/TypeCheckRequestFunctions.cpp

@@ -486,8 +486,8 @@ Type ResultBuilderTypeRequest::evaluate(Evaluator &evaluator,
   return type->mapTypeOutOfContext();
 }
 
-Type GenericTypeParamDeclGetValueTypeRequest::evaluate(Evaluator &evaluator,
-                                             GenericTypeParamDecl *decl) const {
+Type GenericTypeParamDeclGetValueTypeRequest::evaluate(
+    Evaluator &evaluator, const GenericTypeParamDecl *decl) const {
   if (!decl->isValue())
     return Type();