update test to use ivar in implementation instead of class extension

[Wizard]

Summary

using ivar in class extension is not supported in 32-bit architecture of MacOS.

[alexfh]

LG

[Wizard]

add back objc update for identifier naming check.

clang-tools-extra/trunk/clang-tidy/readability/IdentifierNamingCheck.cpp

#define NAMING_KEYS(m) \
     m(Method) \
     m(Typedef) \
     m(TypeTemplateParameter) \
     m(ValueTemplateParameter) \
     m(TemplateTemplateParameter) \
     m(TemplateParameter) \
     m(TypeAlias) \
     m(MacroDefinition) \
+    m(ObjcIvar) \
 
 enum StyleKind {
 #define ENUMERATE(v) SK_ ## v,
   NAMING_KEYS(ENUMERATE)
 #undef ENUMERATE
   SK_Count,
   SK_Invalid
 };
if (Mid.empty())
     Mid = "_";
   return (Style.Prefix + Mid + Style.Suffix).str();
 }
 
 static StyleKind findStyleKind(
     const NamedDecl *D,
     const std::vector<llvm::Optional<IdentifierNamingCheck::NamingStyle>>
         &NamingStyles) {
+  if (isa<ObjCIvarDecl>(D) && NamingStyles[SK_ObjcIvar])
+    return SK_ObjcIvar;
+  
   if (isa<TypedefDecl>(D) && NamingStyles[SK_Typedef])
     return SK_Typedef;
 
   if (isa<TypeAliasDecl>(D) && NamingStyles[SK_TypeAlias])
     return SK_TypeAlias;
 
   if (const auto *Decl = dyn_cast<NamespaceDecl>(D)) {
     if (Decl->isAnonymousNamespace())

clang-tools-extra/trunk/test/clang-tidy/readability-identifier-naming-objc.m

+// RUN: %check_clang_tidy %s readability-identifier-naming %t \
+// RUN: -config='{CheckOptions: \
+// RUN:  [{key: readability-identifier-naming.ObjcIvarPrefix, value: '_'}]}' \
+// RUN: --
+
+@interface Foo
+@end 
+
+@implementation Foo {
+    int _bar;
+    int barWithoutPrefix;
+    // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: invalid case style for objc ivar 'barWithoutPrefix' [readability-identifier-naming]
+    // CHECK-FIXES: int _barWithoutPrefix;
+}
+@end