Try to use readability-identifier-naming check on Clang.

llvm-svn: 266184
diff --git a/clang/.clang-tidy b/clang/.clang-tidy
index 12ef5b9..d10f688 100644
--- a/clang/.clang-tidy
+++ b/clang/.clang-tidy
@@ -1 +1,12 @@
-Checks: '-*,clang-diagnostic-*,llvm-*,misc-*,-misc-unused-parameters'
+Checks: '-*,clang-diagnostic-*,llvm-*,misc-*,-misc-unused-parameters,readability-identifier-naming'
+CheckOptions:
+  - key:             readability-identifier-naming.ClassCase
+    value:           CamelCase
+  - key:             readability-identifier-naming.EnumCase
+    value:           CamelCase
+  - key:             readability-identifier-naming.FunctionCase
+    value:           lowerCase
+  - key:             readability-identifier-naming.UnionCase
+    value:           CamelCase
+  - key:             readability-identifier-naming.VariableCase
+    value:           CamelCase