arm atomic-v6.h: Use eoreqs rather than eorseq to appease GNU as.

[jhb]

Summary

GNU as seems to require the 's' flag after the condition code
rather than before it which seems consistent with the instruction
description for EOR in the ARM ARM. Curiously, however, objdump -d
from binutils displays the instruction as eorseq.

[imp]

If it build with both clang and gcc, this is fine

[andrew]

eorseq is correct as it's created from the eors instruction and eq condition code.

My copy of the ARM ARM (for Armv8/9) has it as EORS{<c>}{<q>} where <c> is the condition code. The <q> is unimportant here as it's to tell the assembler to use a 16 or 32 bit Thumb instruction.

I guess GCC isn't emitting .syntax unified to enable Unified Assembler Language.

[mmel]

Hmm, shouldn't the -masm-syntax-unified be added to gcc CFLAGS? (just guessing, untested)

[jhb]

In D36754#1031820, @mmel wrote:

Hmm, shouldn't the -masm-syntax-unified be added to gcc CFLAGS? (just guessing, untested)

Yes, I just haven't gotten back to testing the right CFLAGS fix.