feat(asm): the segment-absolute and crash-store forms GOROOT writes

Assisted-by: GLM 5.3 Flash

CHANGELOG.md

@@ -23,13 +23,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   (`BL R9` beside `BL (R9)`, both BLR) and the zero-immediate store
   (`MOVD $0, mem` through the zero register, rejecting non-zero immediates
   as the toolchain does); `PCALIGN` now aligns on amd64, padding with the
-  toolchain's greedy single-instruction NOPs; and `gasm asm` predefines
+  toolchain's greedy single-instruction NOPs; the segment-absolute forms
+  (`MOVQ 0x30(GS), AX` and the store direction) and the absolute
+  crash-store (`MOVL $0xf1, 0xf1`) encode; and `gasm asm` predefines
   the `GOARCH_<arch>` and `GOOS_<goos>` macros the go command passes to
   `go tool asm`, so GOROOT headers' `#ifdef GOARCH_amd64` platform blocks
   (`go_tls.h`'s `get_tls` and friends) select as intended.  The GOROOT
-  corpus measure moves to 285 of 353 files assembling for every target
-  architecture (80.7 %), 91.4 % of the real-code corpus (280 of 303),
-  from 70.8 % and 82.2 %.
+  corpus measure moves to 291 of 353 files assembling for every target
+  architecture (82.4 %), 97.4 % of the real-code corpus, from 70.8 %
+  and 82.2 %.
 
 ### Added