[TCWG-1450] Support for Tag_ABI_VFP_args in LLD Needed by FreeBSD in order to switch to LLD for Arm.

[TCWG-1451] Support for v5 and v6 Arm in LLD Tidied up and submitted patches for v5/v6 (branch encoding and compatible thunks), in upstream review.

[TCWG] - Started doing some Jira gardening in preparation for status report - Went back to libfuzzer hang on AArch64 buildbot. Looks like failure to converge on -O2 and above, from the logs and code-generation I suspect that it isn't handling the CINC instruction well (not increasing coverage when the condition passes).