The register set for LDMIA begins at offset 3, not 4. We were previously
missing the short encoding of this instruction in the case where the base
register was the first register in the register set.
Also clean up some dead code:
- The isARMLowRegister check is redundant with what VerifyLowRegs does;
replace with an assert.
- Remove handling of LDMDB instruction, which has no short encoding (and
does not appear in ReduceTable).
Differential Revision: http://reviews.llvm.org/D9485
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236535 91177308-0d34-0410-b5e6-96231b3b80d8
08c531db5f