FMOVQ routes through the MOV load/store machinery in the plain, post-index,
pre-index and static-symbol forms. The Q width carries its size in the opc
field, so the store spelling is opc=10 and the access scales by sixteen;
both come from helpers now instead of the size exponent. The static-symbol
form takes the toolchain's twelve-byte ADRP + ADD + access fallback with the
R_ADDRARM64 pair. The register-to-register and immediate forms stay
rejected, matching the toolchain's own table.
Assisted-by: GLM 5.3 Flash
