Reverting r183529:

This is causing the following error on Darwin:

/Volumes/Sandbox/llvm-clean.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc:282:1: error: 'assertion_failed__282' declared as an array with a negative size
CHECK_TYPE_SIZE(ifconf);
^~~~~~~~~~~~~~~~~~~~~~~
/Volumes/Sandbox/llvm-clean.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc:223:3: note: expanded from macro 'CHECK_TYPE_SIZE'
  COMPILER_CHECK(sizeof(__sanitizer_##TYPE) == sizeof(TYPE))
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Volumes/Sandbox/llvm-clean.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h:239:30: note: expanded from macro 'COMPILER_CHECK'
#define COMPILER_CHECK(pred) IMPL_COMPILER_ASSERT(pred, __LINE__)
                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Volumes/Sandbox/llvm-clean.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h:245:57: note: expanded from macro 'IMPL_COMPILER_ASSERT'
    typedef char IMPL_PASTE(assertion_failed_##_, line)[2*(int)(pred)-1]
                                                        ^~~~~~~~~~~~~~~
/Volumes/Sandbox/llvm-clean.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc:284:1: error: 'assertion_failed__284' declared as an array with a negative size
CHECK_SIZE_AND_OFFSET(ifconf, ifc_ifcu);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Volumes/Sandbox/llvm-clean.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc:228:3: note: expanded from macro 'CHECK_SIZE_AND_OFFSET'
  COMPILER_CHECK(offsetof(__sanitizer_##CLASS, MEMBER) ==          \
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Volumes/Sandbox/llvm-clean.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h:239:30: note: expanded from macro 'COMPILER_CHECK'
#define COMPILER_CHECK(pred) IMPL_COMPILER_ASSERT(pred, __LINE__)
                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Volumes/Sandbox/llvm-clean.src/projects/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h:245:57: note: expanded from macro 'IMPL_COMPILER_ASSERT'
    typedef char IMPL_PASTE(assertion_failed_##_, line)[2*(int)(pred)-1]
                                                        ^~~~~~~~~~~~~~~
R600: Remove unnecessary include

Reviewed-by: Vincent Lejeune <vljn@ovi.com>
R600: Move Subtarget feature definitions into AMDGPU.td

This is the convention used by the other targets.

Reviewed-by: Vincent Lejeune <vljn@ovi.com>
R600: Fix the fetch limits for R600 generation GPUs

Reviewed-by: Vincent Lejeune <vljn@ovi.com>

https://bugs.freedesktop.org/show_bug.cgi?id=64257
Don't cache the instruction and register info from the TargetMachine, because
the internals of TargetMachine could change.

No functionality change intended.