sys: Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

Sync the x86 dis_tables.c with upstream.

This corresponds to the following illumos issues:

5755 want support for Intel FMA instrs
5756 want support for Intel BMI1 instrs
5757 want support for Intel BMI2 instrs
5758 want support for Intel AVX2 instrs
7204 Want broadwell rdseed and adx support
7208 Want stac/clac disasm support
7733 Need SHA Instruction dis support
7756 dis can't handle x86 SSE 3 instructions
7757 want avx2 disasm tests
7758 want SSE 4.1 disasm tests

MFC after: 2 weeks

Move some files that are identical on i386 and amd64 to an x86 subdirectory
rather than keeping duplicate copies.

Discussed with: avg
MFC after: 1 week