PowerPC fixes.

Fix the width and align of bool type on Darwin to be 32bits
while keeping it 8 everywhere else.

Change the definition of va_list to default to SV4 ABI one
and let darwin subtarget override this.

Both changes submitted by Nathan Whitehorn and reviewed
by Rafael Espindola.

llvm-svn: 122956
diff --git a/clang/lib/Basic/TargetInfo.cpp b/clang/lib/Basic/TargetInfo.cpp
index 3828c5a..17de01b 100644
--- a/clang/lib/Basic/TargetInfo.cpp
+++ b/clang/lib/Basic/TargetInfo.cpp
@@ -26,6 +26,7 @@
   TLSSupported = true;
   NoAsmVariants = false;
   PointerWidth = PointerAlign = 32;
+  BoolWidth = BoolAlign = 8;
   IntWidth = IntAlign = 32;
   LongWidth = LongAlign = 32;
   LongLongWidth = LongLongAlign = 64;