nx_aarch64.nx

DEFINITION-COMPLETE: an instruction/ABI emitter exposes one function per emitted form. Emitters with no caller yet are the backend still being built, NOT dead code. Declared so the reachability census buckets them instead of ratcheting a correct steady state as debt. nx_aarch64.nx -- AArch64 Linux AAPCS asm emitter (foundation; session 1). Pure NishiLang port of nxc2/aarch64.c. Lives outside the C side per cardinal feedback-no-nxc2-c-extension-only-nishilang-forward. This file is the FOUNDATION layer; sessions 2-N fill in the per-opcode IR-to-asm dispatch and wire into nxc.nx as --target aarch64. Session 1 scope (this file): * AArch64 register name table (AAPCS) * function prologue / epilogue (stp x29,x30 / add x29,sp / sub sp) * .text / .rodata section directives * label emission * literal constant load (movz + movk chain for full 64-bit imm) * register-to-register move (mov xD, xS) * PIC-aware address load (adrp + add for label) * add / sub register-to-register (add xD, xS, xN / sub) * syscall (svc #0 -- the ARM64 supervisor call) * .asciz string literal emission with byte-escape Sessions 2-N (deferred): * IR-instruction dispatch (binop / cmp / branch / call / load / store / GEP / phi / return / tail_call / inline_asm) * stack-machine slot layout per nxc2/aarch64.c * regalloc integration (linear-scan with AAPCS-preserved regs) * NEON SIMD (mov vD.16b, vS.16b / add vD.4s, vS.4s, vN.4s) * full nxc.nx wiring as --target aarch64 dispatch Output format: GNU AS unified syntax (no AT&T % prefix), Linux AAPCS ABI, position-independent via adrp/add for label refs. Byte-compatible with `aarch64-linux-gnu-as`. genealogy_id: nxc2_aarch64_c_2026 + aapcs64_v1 lineage_id: nx_aarch64_foundation_v1 nx_safety_envelope: intended_use: "Foundation emit library for AArch64 Linux AAPCS assembly text. Per-primitive functions