SimplifyAddress to handle either a 12-bit unsigned offset or the ARM +/-imm8
offsets (addressing mode 3). This enables a load followed by an integer
extend to be folded into a single load.
For example:
ldrb r1, [r0] ldrb r1, [r0]
uxtb r2, r1 =>
mov r3, r2 mov r3, r1
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144488 91177308-0d34-0410-b5e6-96231b3b80d8