Addressing Jordan's code review feedbacks. NFC

Author: nkcsgexi

lib/Sema/CSDiag.cpp

@@ -2410,17 +2410,18 @@ findCorrectEnumCaseName(MetatypeType *MetaTy, LookupResult &Result,
                         DeclName memberName) {
   if (!memberName.isSimpleName())
     return DeclName();
-  if (!MetaTy->getInstanceType()->is<EnumType>())
+  if (!MetaTy->getInstanceType()->is<EnumType>() &&
+      !MetaTy->getInstanceType()->is<BoundGenericEnumType>())
     return DeclName();
-  std::vector<DeclName> candidates;
+  llvm::SmallVector<DeclName, 4> candidates;
   for (auto &correction : Result) {
     DeclName correctName = correction.Decl->getFullName();
     if (!correctName.isSimpleName())
       continue;
     if (!isa<EnumElementDecl>(correction.Decl))
       continue;
     if (correctName.getBaseName().str().
-          compare_lower(memberName.getBaseName().str()) == 0)
+          equals_lower(memberName.getBaseName().str()))
       candidates.push_back(correctName);
   }
   if (candidates.size() == 1)

test/NameBinding/name_lookup.swift

@@ -541,3 +541,13 @@ func foo() {
   _ = MyEnum.Two // expected-error {{enum type 'MyEnum' has no case 'Two'; did you mean 'two'}}{{14-17=two}}
   _ = MyEnum.OneTwoThree // expected-error {{enum type 'MyEnum' has no case 'OneTwoThree'; did you mean 'oneTwoThree'}}{{14-25=oneTwoThree}}
 }
+
+enum MyGenericEnum<T> {
+  case one(T)
+  case oneTwo(T)
+}
+
+func foo1() {
+  _ = MyGenericEnum<Int>.One // expected-error {{enum type 'MyGenericEnum<Int>' has no case 'One'; did you mean 'one'}}{{26-29=one}}
+  _ = MyGenericEnum<Int>.OneTwo // expected-error {{enum type 'MyGenericEnum<Int>' has no case 'OneTwo'; did you mean 'oneTwo'}}{{26-32=oneTwo}}
+}