AArch64: Add explicit all-nil qualifiers to opcode table
The AArch64 opcode table now explicitly specifies nil qualifiers, preparing for a change in the value of AARCH64_OPND_QLF_NIL.
This change adds explicit all-nil qualifiers to the AArch64 opcode table. This prepares the codebase for a future change where AARCH64_OPND_QLF_NIL will have a nonzero enum value.
In Details
The AArch64 opcode table (opcodes/aarch64-tbl.h) defines the structure of AArch64 instructions. The QL_NIL* macros define qualifier sequences with explicit NIL qualifiers. This change anticipates a future change in the value of AARCH64_OPND_QLF_NIL.
For Context
When assembling AArch64 instructions, the assembler uses an opcode table to determine the valid instructions and their operands. This table uses qualifiers to specify the type of each operand. This commit adds explicit "nil" qualifiers to the opcode table, which are used when an operand does not have a specific type. This change ensures that the assembler will continue to function correctly when the numerical representation of the "nil" qualifier is changed in the future.