[ms-inline-asm] Cleanup MS style inline assembly parsing.

Specifically, improve the handling of whitespace, stop saving tokens that are
in comments and fix the case where we have a comment followed by a closing brace
on the next line.

Unfortunately, there's no easy way of testing this code.

llvm-svn: 158367
diff --git a/clang/test/Parser/ms-inline-asm.c b/clang/test/Parser/ms-inline-asm.c
index b1af23e..3a1efb0 100644
--- a/clang/test/Parser/ms-inline-asm.c
+++ b/clang/test/Parser/ms-inline-asm.c
@@ -20,6 +20,13 @@
   __asm int 4
   return 10;
 }
-int t7() { // expected-note {{to match this}}
+int t7() {
+  __asm {
+    push ebx
+    mov ebx, 0x07
+    pop ebx
+  }
+}
+int t_fail() { // expected-note {{to match this}}
   __asm
   __asm { // expected-error 3 {{expected}} expected-note {{to match this}}