Backport changes from llvm/.clang_tidy to clang/.clang_tidy configs

Summary: LLVM .clang_tidy seems to be more up-to-date.

Reviewers: alexfh, simark

Reviewed By: alexfh

Subscribers: simark, cfe-commits

Differential Revision: https://reviews.llvm.org/D44628

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@327984 91177308-0d34-0410-b5e6-96231b3b80d8

.clang-tidy

@@ -5,8 +5,13 @@ CheckOptions:
   - key:             readability-identifier-naming.EnumCase
     value:           CamelCase
   - key:             readability-identifier-naming.FunctionCase
-    value:           lowerCase
+    value:           camelBack
+  - key:             readability-identifier-naming.MemberCase
+    value:           CamelCase
+  - key:             readability-identifier-naming.ParameterCase
+    value:           CamelCase
   - key:             readability-identifier-naming.UnionCase
     value:           CamelCase
   - key:             readability-identifier-naming.VariableCase
     value:           CamelCase
+