`mrs x0, cntvct_el0` came back out of the disassembler as
`mrs x0, #24322`. The 230 sysreg constants were already there and the
encoding was byte-exact against llvm-mc -- the printer simply had no
SYS_REG handling, so the packed 15-bit field printed as an immediate.
Nothing an assembler would take back.
Adds a value -> name table (sorted, binary searched) and prints that
operand by name for MRS, and for the MSR form that takes one. MSR's
other form holds a PSTATE field selector in the same slot, which is a
different namespace; the two are told apart by whether the second
operand is a register or an immediate.
Six encodings carry two names, so a round-trip can come back spelled as
the sibling; the first by source order wins.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018UmHLRF11EoWwNWCJ7JGaA
01bdf7522c