This patch is to fix radar://8426430. It is about llvm support of __builtin_debugtrap()
which is supposed to consistently raise SIGTRAP across all systems. In contrast,
__builtin_trap() behave differently on different systems. e.g. it raises SIGTRAP on ARM, and
SIGILL on X86. The purpose of __builtin_debugtrap() is to consistently provide "trap"
functionality, in the mean time preserve the compatibility with on gcc on __builtin_trap().

  The X86 backend is already able to handle debugtrap(). This patch is to:
  1) make front-end recognize "__builtin_debugtrap()" (emboddied in the one-line change to Clang).
  2) In DAG legalization phase, by default, "debugtrap" will be replaced with "trap", which
     make the __builtin_debugtrap() "available" to all existing ports without the hassle of
     changing their code.
  3) If trap-function is specified (via -trap-func=xyz to llc), both __builtin_debugtrap() and
     __builtin_trap() will be expanded into the function call of the specified trap function.
    This behavior may need change in the future.

  The provided testing-case is to make sure 2) and 3) are working for ARM port, and we
already have a testing case for x86. 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166300 91177308-0d34-0410-b5e6-96231b3b80d8
tests: Stop mangling '-vg' into the triple, we don't use this currently.
 - Also, lit is going to get a valgrind feature, instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166302 91177308-0d34-0410-b5e6-96231b3b80d8
lit: Add 'valgrind' and 'valgrind-leaks' features when valgrind is used.
 - These can be used with the XFAIL options.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166303 91177308-0d34-0410-b5e6-96231b3b80d8
lit: Remove support for XTARGET.

 - The XTARGET feature (inherited from old DG tests) was just confusing (and
   barely ever used). The same effect can now be achieved with a combination of
   the more useful REQUIRES and XFAIL.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166305 91177308-0d34-0410-b5e6-96231b3b80d8
lit: Rename the valgrind leaks feature to match what is currently used
(vg_leak).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166306 91177308-0d34-0410-b5e6-96231b3b80d8
[ms-inline asm] Add a MCAsmParserSemaCallback to the TargetAsmParser.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166308 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a build error for ocaml bindings that was introduced with the TargetData --> DataLayout changes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166309 91177308-0d34-0410-b5e6-96231b3b80d8
SimplifyLibcalls: The return value of ffsll is always i32, even when the input is zero.

Fixes PR13028.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166313 91177308-0d34-0410-b5e6-96231b3b80d8
Add 'IntrNoReturn' for longjmp intrinsics



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166314 91177308-0d34-0410-b5e6-96231b3b80d8
[ms-inline asm] Have the TargetParser callback to Sema to determine the size of
a memory operand.  Retain this information and then add the sizing directives
to the IR.  This allows the backend to do proper instruction selection.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166316 91177308-0d34-0410-b5e6-96231b3b80d8