Simplify the scheme used for keywords, and change the classification 
scheme to be more useful.

The new scheme introduces a set of categories that should be more 
readable, and also reflects what we want to consider as an extension 
more accurately.  Specifically, it makes the "what is a keyword" 
determination accurately reflect whether the keyword is a GNU or 
Microsoft extension.

I also introduced separate flags for keyword aliases; this is useful 
because the classification of the aliases is mostly unrelated to the 
classification of the original keyword.

This patch treats anything that's in the implementation 
namespace (prefixed with "__", or "_X" where "X" is any upper-case 
letter) as a keyword without marking it as an extension.  This is 
consistent with the standards in that an implementation is allowed to define 
arbitrary extensions in the implementation namespace without violating 
the standard. This gets rid of all the nasty "extension used" warnings 
for stuff like __attribute__ in -pedantic mode.  We still warn for 
extensions outside of the the implementation namespace, like typeof.
If someone wants to implement -Wextensions or something like that, we 
could add additional information to the keyword table.

This also removes processing for the unused "Boolean" language option; 
such an extension isn't supported on any other C implementation, so I 
don't see any point to adding it.

The changes to test/CodeGen/inline.c are required because previously, we 
weren't actually disabling the "inline" keyword in -std=c89 mode.

I'll remove Boolean and NoExtensions from LangOptions in a follow-up 
commit.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@70281 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Sema/i-c-e.c b/test/Sema/i-c-e.c
index 6afe035..de27966 100644
--- a/test/Sema/i-c-e.c
+++ b/test/Sema/i-c-e.c
@@ -61,6 +61,6 @@
 int illegaldiv2[1/0]; // expected-error {{variable length array declaration not allowed at file scope}}
 int illegaldiv3[INT_MIN / -1]; // expected-error {{variable length array declaration not allowed at file scope}}
 
-int chooseexpr[__builtin_choose_expr(1, 1, expr)]; // expected-warning {{extension used}}
-int realop[(__real__ 4) == 4 ? 1 : -1]; // expected-warning {{extension used}}
-int imagop[(__imag__ 4) == 0 ? 1 : -1]; // expected-warning {{extension used}}
+int chooseexpr[__builtin_choose_expr(1, 1, expr)];
+int realop[(__real__ 4) == 4 ? 1 : -1];
+int imagop[(__imag__ 4) == 0 ? 1 : -1];