[llvm] r253675 - Handle ARMv6-J as an alias, instead of fake architecture

[Meador Inge via llvm-commits]

On Fri, Nov 20, 2015 at 10:46 AM, Artyom Skrobov via llvm-commits
<llvm-commits at lists.llvm.org> wrote:

> The J-bit (Jazelle support) is irrelevant to LLVM, and it doesn't
> affect code generation, attributes, optimizations, or anything else,
> apart from selecting the default CPU.

I *does* affect the builtin macros.  After this patch I see:

  $ ./bin/clang -target arm-none-linux-gnu -mfloat-abi=soft
-march=armv6j -dM -E -o - -x c - < /dev/null | grep ARM_ARCH_6

  #define __ARM_ARCH_6__ 1

Before it was:

  #define __ARM_ARCH_6J__ 1

GCC defines it as '__ARM_ARCH_6J__'.
Changing the builtin macros could break existing code that compiled
fine with GCC.

-- Meador