Merge r316035 into the 5.0 branch: fixes an assertion failure while building Firefox for AArch64

[DimitryAndric]

Bugzilla Link	35024
Resolution	FIXED
Resolved on	Nov 28, 2017 14:02
Version	5.0
OS	All
Blocks	#33840
CC	@tstellar
Fixed by commit(s)	r316035 r319231

Extended Description

Please merge https://reviews.llvm.org/rL316035 into the 5.0 branch. This fixes 'Assertion failed: (isReg() && "This is not a register operand!"), function getReg, file /home/dim/src/llvm-trunk/include/llvm/CodeGen/MachineOperand.h, line 278.' while building Firefox for AArch64. (See bug 34979.)

[DimitryAndric]

assigned to @tstellar

[tstellar]

Tim, is this OK to merge?

[TNorthover]

Yep, I think it's reasonable.

[tstellar]

Merged: r319231