[15] RFR (L): 8241436: C2: Factor out C2-specific code from MacroAssembler

[Vladimir Ivanov]

>> I took the liberty and refactored aarch64, arm32, ppc64, s390x code
>> along the way. I did a cross-build, but I ask maintainers to verify that
>> it doesn't break anything.
> I'm hoping I'll be able to test this on AArch64 today.

Thank you, Andrew. I'll wait for the results.

Best regards,
Vladimir Ivanov