AST: Add typeCheckFunctionBodies parameter to getUniqueUnderlyingTypeSubstitutions()

Author: slavapestov

include/swift/AST/Decl.h

@@ -3659,7 +3659,8 @@ class OpaqueTypeDecl final :
 
   /// The substitutions that map the generic parameters of the opaque type to
   /// the unique underlying types, when that information is known.
-  std::optional<SubstitutionMap> getUniqueUnderlyingTypeSubstitutions() const;
+  std::optional<SubstitutionMap> getUniqueUnderlyingTypeSubstitutions(
+      bool typeCheckFunctionBodies=true) const;
 
   void setUniqueUnderlyingTypeSubstitutions(SubstitutionMap subs) {
     assert(!UniqueUnderlyingType.has_value() && "resetting underlying type?!");

lib/AST/Decl.cpp

@@ -10840,7 +10840,11 @@ bool OpaqueTypeDecl::exportUnderlyingType() const {
 }
 
 std::optional<SubstitutionMap>
-OpaqueTypeDecl::getUniqueUnderlyingTypeSubstitutions() const {
+OpaqueTypeDecl::getUniqueUnderlyingTypeSubstitutions(
+    bool typeCheckFunctionBodies) const {
+  if (!typeCheckFunctionBodies)
+    return UniqueUnderlyingType;
+
   return evaluateOrDefault(getASTContext().evaluator,
                            UniqueUnderlyingTypeSubstitutionsRequest{this}, {});
 }