Improve clang-format's understanding of casts.

This fixes llvm.org/PR14684.

Before: int *pa = (int *) & a;
After:  int *pa = (int *)&a;

We still don't understand all kinds of casts. I added a FIXME to
address that.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172056 91177308-0d34-0410-b5e6-96231b3b80d8
Fix layout of blocks inside statements.

Previously, we would not indent:
SOME_MACRO({
  int i;
});
correctly. This is fixed by adding the trailing }); to the unwrapped
line starting with SOME_MACRO({, so the formatter can correctly match
the braces and indent accordingly.

Also fixes incorrect parsing of initializer lists, like:
int a[] = { 1 };

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172058 91177308-0d34-0410-b5e6-96231b3b80d8