Move if-let special case into getTypeReprOrParentPatternTypeRepr

As suggested during PR review.

This mechanism seems to be general enough to fit into
getTypeReprOrParentPatternRepr.

Author: fwcd

lib/AST/Decl.cpp

@@ -5806,11 +5806,24 @@ void VarDecl::setNamingPattern(NamedPattern *Pat) {
 }
 
 TypeRepr *VarDecl::getTypeReprOrParentPatternTypeRepr() const {
-  if (auto *param = dyn_cast<ParamDecl>(this))
-    return param->getTypeRepr();
-
-  if (auto *parentPattern = dyn_cast_or_null<TypedPattern>(getParentPattern()))
-    return parentPattern->getTypeRepr();
+  if (auto *Param = dyn_cast<ParamDecl>(this))
+    return Param->getTypeRepr();
+
+  auto *ParentPattern = getParentPattern();
+
+  if (auto *TyPattern = dyn_cast_or_null<TypedPattern>(ParentPattern))
+    return TyPattern->getTypeRepr();
+
+  // Handle typed if/guard/while-let as a special case (e.g. `if let x: Int
+  // = Optional.some(4)`), since the `TypedPattern` is not the top-level
+  // pattern here - instead it is an implicit `OptionalSomePattern`
+  if (auto *SomePattern =
+          dyn_cast_or_null<OptionalSomePattern>(ParentPattern)) {
+    if (auto *TyPattern =
+            dyn_cast<TypedPattern>(SomePattern->getSubPattern())) {
+      return TyPattern->getTypeRepr();
+    }
+  }
 
   return nullptr;
 }

lib/IDE/IDETypeChecking.cpp

@@ -808,20 +808,6 @@ class VariableTypeCollector : public SourceEntityWalker {
       auto TyOffset = getTypeOffset(Buffer.str());
       bool HasExplicitType =
           VD->getTypeReprOrParentPatternTypeRepr() != nullptr;
-      // Handle typed if/guard/while-let as a special case (e.g. `if let x: Int
-      // = Optional.some(4)`), since the `TypedPattern` is not the top-level
-      // pattern here - instead it is an implicit `OptionalSomePattern`
-      if (!HasExplicitType) {
-        if (auto *somePattern =
-                dyn_cast_or_null<OptionalSomePattern>(VD->getParentPattern())) {
-          if (somePattern->isImplicit()) {
-            if (auto *typedPattern =
-                    dyn_cast<TypedPattern>(somePattern->getSubPattern())) {
-              HasExplicitType = typedPattern->getTypeRepr() != nullptr;
-            }
-          }
-        }
-      }
       // Add the type information to the result list.
       Results.emplace_back(VarOffset, VarLength, HasExplicitType, TyOffset);
     }