[x32] Fix FrameIndex check in SelectLEA64_32Addr

Summary:
Fixes http://llvm.org/bugs/show_bug.cgi?id=20016 reproducible on new
lea-5.ll case.
Also use RSP/RBP for x32 lea to save 1 byte used for 0x67 prefix in
ESP/EBP case.

Test Plan: lea tests modified to include x32/nacl and new test added

Reviewers: nadav, dschuff, t.p.northover

Subscribers: llvm-commits, zinovy.nis

Differential Revision: http://reviews.llvm.org/D4929

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216065 91177308-0d34-0410-b5e6-96231b3b80d8
Optimize ZERO_EXTEND and SIGN_EXTEND in both SelectionDAG Builder and type
legalization stage. With those two optimizations, fewer signed/zero extension
instructions can be inserted, and then we can expose more opportunities to
Machine CSE pass in back-end.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216066 91177308-0d34-0410-b5e6-96231b3b80d8
Silencing an MSVC C4334 warning ('<<' : result of 32-bit shift implicitly converted to 64 bits (was 64-bit shift intended?)). NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216067 91177308-0d34-0410-b5e6-96231b3b80d8