Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"

Re-enable commit r323991 now that r325931 has been committed to make
MachineOperand::isRenamable() check more conservative w.r.t. code
changes and opt-in on a per-target basis.

llvm-svn: 326208
diff --git a/llvm/test/CodeGen/X86/safestack_inline.ll b/llvm/test/CodeGen/X86/safestack_inline.ll
index ed93c49..0fc53556 100644
--- a/llvm/test/CodeGen/X86/safestack_inline.ll
+++ b/llvm/test/CodeGen/X86/safestack_inline.ll
@@ -25,6 +25,6 @@
 
 ; CALL: callq __safestack_pointer_address
 ; CALL: movq %rax, %[[A:.*]]
-; CALL: movq (%[[A]]), %[[B:.*]]
+; CALL: movq (%rax), %[[B:.*]]
 ; CALL: leaq -16(%[[B]]), %[[C:.*]]
 ; CALL: movq %[[C]], (%[[A]])