Backport ece79f47083babcabde3700c67b90ef19967a5b3 for 10.0.1

[llvmbot]

Bugzilla Link	46301
Resolution	FIXED
Resolved on	Jun 17, 2020 15:58
Version	10.0
OS	Linux
Blocks	#44654
Reporter	LLVM Bugzilla Contributor
CC	@topperc,@RKSimon,@rotateright,@tstellar
Fixed by commit(s)	ece79f4 3209077

Extended Description

Please cherry-pick https://reviews.llvm.org/D77031 into 10.0.1.
It fixes miscompiation reported in rust-lang/rust#73151.

commit ece79f47083babcabde3700c67b90ef19967a5b3
Author: Yuanfang Chen <yuanfang.chen@sony.com>
Date:   Sun Mar 29 13:01:42 2020 -0700

    [X86] make sure POP has implicit def/use of stack pointer when materializing 8-bit immediates for minsize

[llvmbot]

assigned to @topperc

[tstellar]

Craig, what do you think about backporting this?

https://reviews.llvm.org/rGece79f47083babcabde3700c67b90ef19967a5b3

[topperc]

This looks ok to backport

[tstellar]

Merged: 3209077