Reviewed by Gavin Barraclough.

        Defines two pseudo-platforms for ARM and Thumb-2 instruction set.
        https://bugs.webkit.org/show_bug.cgi?id=29122

        Introduces WTF_PLATFORM_ARM_TRADITIONAL and WTF_PLATFORM_ARM_THUMB2
        macros on ARM platforms. The PLATFORM(ARM_THUMB2) should be used
        when Thumb-2 instruction set is the required target. The
        PLATFORM(ARM_TRADITIONAL) is for generic ARM instruction set. In
        case where the code is common the PLATFORM(ARM) have to be used.

        * assembler/ARMAssembler.cpp:
        * assembler/ARMAssembler.h:
        * assembler/ARMv7Assembler.h:
        * assembler/MacroAssembler.h:
        * assembler/MacroAssemblerARM.cpp:
        * assembler/MacroAssemblerARM.h:
        * assembler/MacroAssemblerCodeRef.h:
        (JSC::MacroAssemblerCodePtr::MacroAssemblerCodePtr):
        * jit/ExecutableAllocator.h:
        * jit/JIT.h:
        * jit/JITInlineMethods.h:
        (JSC::JIT::beginUninterruptedSequence):
        (JSC::JIT::preserveReturnAddressAfterCall):
        (JSC::JIT::restoreReturnAddressBeforeReturn):
        (JSC::JIT::restoreArgumentReference):
        (JSC::JIT::restoreArgumentReferenceForTrampoline):
        * jit/JITOpcodes.cpp:
        * jit/JITStubs.cpp:
        (JSC::JITThunks::JITThunks):
        * jit/JITStubs.h:
        * wtf/Platform.h:
        * yarr/RegexJIT.cpp:
        (JSC::Yarr::RegexGenerator::generateEnter):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@48525 268f45cc-cd09-0410-ab3c-d52691b4dbfc