Cleanup ARM load/store wide and remove unused param s_reg.

Use a single LDRD/VLDR instruction for wide load/store on
ARM, adjust the base pointer if needed. Remove unused
parameter s_reg from LoadBaseDisp(), LoadBaseIndexedDisp()
and StoreBaseIndexedDisp() on all architectures.

Change-Id: I25a9a42d523a68addbc11abe44ddc55a4401df98
17 files changed