xacquire/xrelease parsed improperly

[Keno]

Bugzilla Link	31080
Version	3.9
OS	All
Blocks	#11360
CC	@topperc

Extended Description

$ llvm-mc
xrelease lock subq $1,4(%rip)
	.text
<stdin>:1:15: error: unexpected token in argument list
xrelease lock subq $1,4(%rip)
              ^

gcc accepts this fine. For now treating is as a separate instruction with ; works,
but seems a little wrong.

xrelease; lock subq $1,4(%rip)

[llvmbot]

Hi,
I checked this issue with the current trunk: everythig works perfectly:

atischenko@ip-172-31-21-62:~/workspaces/trunk/build/bin$ cat test.s
xrelease lock subq $1,4(%rip);

atischenko@ip-172-31-21-62:~/workspaces/trunk/build/bin$ llvm-mc -show-encoding test.s
.text
xrelease # encoding: [0xf3]
lock subq $1, 4(%rip) # encoding: [0xf0,0x48,0x83,0x2d,0x03,0x00,0x00,0x00,0x01]

atischenko@ip-172-31-21-62:~/workspaces/trunk/build/bin$ cat test.txt
0xf3, 0xf0,0x48,0x83,0x2d,0x03,0x00,0x00,0x00,0x01

atischenko@ip-172-31-21-62:~/workspaces/trunk/build/bin$ llvm-mc -disassemble test.txt
.text
xrelease
lock
subq $1, 3(%rip)

As you see both assembler and dissassembler produce correct results.
It seems we should close the bug, right?