Fixed warnings on redefine keywords and reserved ids.

Repared support for warnings -Wkeyword-macro and -Wreserved-id-macro.
The warning -Wkeyword-macro now is not issued in patterns that are used
in configuration scripts:

    #define inline

also for 'const', 'extern' and 'static'. If macro repalcement is identical
to macro name, the warning also is not issued:

    #define volatile volatile

And finally if macro replacement is also a keyword identical to the replaced
one but decorated with leading/trailing underscores:

    #define inline __inline
    #define inline __inline__
    #define inline _inline // in MSVC compatibility mode

Warning -Wreserved-id-macro is off by default, it could help catching
things like:

    #undef __cplusplus

llvm-svn: 224512
diff --git a/clang/test/Preprocessor/macro-reserved-cxx11.cpp b/clang/test/Preprocessor/macro-reserved-cxx11.cpp
new file mode 100644
index 0000000..a740ff6
--- /dev/null
+++ b/clang/test/Preprocessor/macro-reserved-cxx11.cpp
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++11 -pedantic -verify %s
+
+#define for 0    // expected-warning {{keyword is hidden by macro definition}}
+#define final 1  // expected-warning {{keyword is hidden by macro definition}}
+#define override // expected-warning {{keyword is hidden by macro definition}}
+
+int x;