Check for less than 0 in shuffle mask instead of -1. It's more consistent with other code related to shuffles and easier to implement in compiled code.
Formatter: After case blocks, "break" goes on the same line as the "}", PR14907.

Before:
switch (foo) {
case a: {
  int a = g();
  h(a);
}
  break;
}

Now:
switch (foo) {
case a: {
  int a = g();
  h(a);
} break;
}
Makefile: Corresponding to r172787, "Backend.cpp: s/TARGET_NAME/TARGET_TRIPLE/ Also TARGET_TRIPLE can be normalized as well as TARGET_NAME."

I forgot to commit it by mistake, sorry.
[sanitizer] reapply r172719, r172721-172723, r172725, and also fix the warning on Mac.
Make more use of is128BitVector/is256BitVector in place of getSizeInBits() == 128/256.
Spelling fix: extened->extended. Trailing whitespace in same function.