CompilerRT: .align was supposed to be power-of-aligned in this case

Use .balign instead of .p2align 3.  This should fix the buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@208585 91177308-0d34-0410-b5e6-96231b3b80d8
__clear_cache: decorate with COMPILER_RT_EXPORT

Use COMPILER_RT_EXPORT rather than COMPILER_RT_ABI for this function.  Adding an
explicit PCS standard to the function causes a mismatch between the
declarations.  Furthermore, the function is implemented in C, and should take
the CC based on the target triple.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@208591 91177308-0d34-0410-b5e6-96231b3b80d8
builtins: add missing file

Add (missing) definition of COMPILER_RT_EXPORT which is meant to be used for
decorating functions that are meant to be exported.  This is useful for
platforms where exports and imports must be decorated explicitly (i.e. Windows).

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@208593 91177308-0d34-0410-b5e6-96231b3b80d8