Include debug info for types referenced only via explicit cast expressions.

Most of the debug info emission is powered essentially from function
definitions - if we emit the definition of a function, we emit the types
of its parameters, the members of those types, and so on and so forth.

For types that aren't referenced even indirectly due to this - because
they only appear in temporary expressions, not in any named variable, we
need to explicitly emit/add them as is done here. This is not the only
case of such code, and we might want to consider handling "void
func(void*); ... func(new T());" (currently debug info for T is not
emitted) at some point, though GCC doesn't. There's a much broader
solution to these issues, but it's a lot of work for possibly marginal
gain (but might help us improve the default -fno-standalone-debug
behavior to be even more aggressive in some places). See the original
review thread for more details.

Patch by jyoti allur (jyoti.yalamanchili@gmail.com)!

Differential Revision: http://reviews.llvm.org/D2498

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@218390 91177308-0d34-0410-b5e6-96231b3b80d8
clang-format: Don't let -style=Chromium imply c++03 template formatting.

Chromium's now using some c++11 language features, so it's now fine that
clang-format produces vector<vector<int>>.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@218392 91177308-0d34-0410-b5e6-96231b3b80d8
Downgrade error about stdcall decls with no prototype to a warning

Fixes PR21027.  The MIDL compiler produces code that does this.

If we wanted to improve the warning, I think we could do this:
  void __stdcall f(); // Don't warn without -Wstrict-prototypes.
  void g() {
    f(); // Might warn, the user probably meant for f to take no args.
    f(1, 2, 3); // Warn, we have no idea what args f takes.
    f(1); // Error, this is insane, one of these calls is broken.
  }

Reviewers: thakis

Differential Revision: http://reviews.llvm.org/D5481

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@218394 91177308-0d34-0410-b5e6-96231b3b80d8