Two changes relevant to LEA and x32:

1) allows the use of RIP-relative addressing in 32-bit LEA instructions under
   x86-64 (ILP32 and LP64)
2) separates the size of address registers in 64-bit LEA instructions from
   control by ILP32/LP64.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174208 91177308-0d34-0410-b5e6-96231b3b80d8