Fix typo

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175530 91177308-0d34-0410-b5e6-96231b3b80d8
Move LLVM_LIBRARY_VISIBILITY for consistency with what was done to
PPCJITInfo.cpp in r175394.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175531 91177308-0d34-0410-b5e6-96231b3b80d8
Clean up HiPE prologue emission a bit and avoid signed arithmetic tricks.

No intended functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175536 91177308-0d34-0410-b5e6-96231b3b80d8