Pull in r316035 from upstream llvm trunk (by Tim Northover):
AArch64: account for possible frame index operand in compares. If the address of a local is used in a comparison, AArch64 can fold the address-calculation into the comparison via "adds". Unfortunately, a couple of places (both hit in this one test) are not ready to deal with that yet and just assume the first source operand is a register.
This should fix an assertion failure while building the test suite of
www/firefox for AArch64.
PR: 223048
MFC after: 3 days