Remove top-level Clang -fsanitize= flags for optional ASan features.

Init-order and use-after-return modes can currently be enabled
by runtime flags. use-after-scope mode is not really working at the
moment.

The only problem I see is that users won't be able to disable extra
instrumentation for init-order and use-after-scope by a top-level Clang flag.
But this instrumentation was implicitly enabled for quite a while and
we didn't hear from users hurt by it.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@210924 91177308-0d34-0410-b5e6-96231b3b80d8
Adds a Pragma spelling for attributes to tablegen and makes use of it for loop
hint attributes. Includes tests for pragma printing and for attribute order
which is incorrectly reversed by ParsedAttributes.

Reviewed by Aaron Ballman


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@210925 91177308-0d34-0410-b5e6-96231b3b80d8
[PPC64LE] Run some existing Altivec tests on powerpc64le as well

There are several Altivec tests that formerly ran only on big-endian
targets (and in some cases only on 32-bit targets).  It is useful to
verify these on little-endian targets as well.

While testing these, I discovered a typo in <altivec.h>.  This is also
fixed by this patch.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@210928 91177308-0d34-0410-b5e6-96231b3b80d8