[AST] Fix circular reference with implicit some

getPotentiallyOpaqueGenericParams has a redundant call to check if
declarations contain any opaque type representations. We don't need
to check this here. Instead we can simply collect the result type
representaions without the additional checks.

Author: angela-laar

include/swift/AST/Decl.h

@@ -2767,6 +2767,9 @@ class ValueDecl : public Decl {
   /// some Q), or we might have a `NamedOpaqueReturnTypeRepr`.
   TypeRepr *getOpaqueResultTypeRepr() const;
 
+  /// Get the representative for this value's result type, if it has one.
+  TypeRepr *getResultTypeRepr() const;
+
   /// Retrieve the attribute associating this declaration with a
   /// result builder, if there is one.
   CustomAttr *getAttachedResultBuilder() const;

lib/AST/ASTScopeCreation.cpp

@@ -893,7 +893,7 @@ namespace {
   /// Retrieve the opaque generic parameter list if present, otherwise the normal generic parameter list.
   template<typename T>
   GenericParamList *getPotentiallyOpaqueGenericParams(T *decl) {
-    if (auto opaqueRepr = decl->getOpaqueResultTypeRepr()) {
+    if (auto opaqueRepr = decl->getResultTypeRepr()) {
       if (auto namedOpaque = dyn_cast<NamedOpaqueReturnTypeRepr>(opaqueRepr)) {
         return namedOpaque->getGenericParams();
       }

lib/AST/Decl.cpp

@@ -3058,7 +3058,8 @@ void ValueDecl::setOverriddenDecls(ArrayRef<ValueDecl *> overridden) {
   request.cacheResult(overriddenVec);
 }
 
-TypeRepr *ValueDecl::getOpaqueResultTypeRepr() const {
+// To-Do: Replce calls to getOpaqueResultTypeRepr with getResultTypeRepr()
+TypeRepr *ValueDecl::getResultTypeRepr() const {
   TypeRepr *returnRepr = nullptr;
   if (auto *VD = dyn_cast<VarDecl>(this)) {
     if (auto *P = VD->getParentPattern()) {
@@ -3069,7 +3070,7 @@ TypeRepr *ValueDecl::getOpaqueResultTypeRepr() const {
         P = P->getSemanticsProvidingPattern();
         if (auto *NP = dyn_cast<NamedPattern>(P)) {
           assert(NP->getDecl() == VD);
-          (void) NP;
+          (void)NP;
 
           returnRepr = TP->getTypeRepr();
         }
@@ -3083,6 +3084,14 @@ TypeRepr *ValueDecl::getOpaqueResultTypeRepr() const {
     returnRepr = SD->getElementTypeRepr();
   }
 
+  return returnRepr;
+}
+
+TypeRepr *ValueDecl::getOpaqueResultTypeRepr() const {
+  TypeRepr *returnRepr = nullptr;
+
+  returnRepr = this->getResultTypeRepr();
+
   auto *dc = getDeclContext();
   auto &ctx = dc->getASTContext();