Recommitted fix for PR18931, with extended tests set.
Issue subject: Crash using integrated assembler with immediate arithmetic

Fix description:
Expressions like 'cmp r0, #(l1 - l2) >> 3' could not be evaluated on asm parsing stage,
since it is impossible to resolve labels on this stage. In the end of stage we still have
expression (MCExpr).
Then, when we want to encode it, we expect it to be an immediate, but it still an expression.
Patch introduces a Fixup (MCFixup instance), that is processed after main encoding stage.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205094 91177308-0d34-0410-b5e6-96231b3b80d8
[PowerPC] VSX instruction latency corrections

The vector divide and sqrt instructions have high latencies, and the scalar
comparisons are like all of the others. On the P7, permutations take an extra
cycle over purely-simple vector ops.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205096 91177308-0d34-0410-b5e6-96231b3b80d8