vms-2655: joint-e2e port link opts into the CRTL->RMS veneer + LIBVMSRMS$SHR (rung 3)

[baron-3dl]

Summary

• Rung 3 of vms-b4f (rd vms-2655): build-joint-image.sh gains an opt-in JOINT_CRTL_RMS_VENEER=1 (default 0, byte-identical otherwise) that composes rung 2's two-pass DECC$SHR veneer bootstrap (decc-veneer/build-decc-veneer.sh) into the port-link recipe — pass 1 raises the OVMX producer graph through LIBVMSRMS$SHR, pass 2 rebuilds DECC$SHR with ALPHA_CRTL_RMS_USE so decc$fopen/fwrite/fread/fclose alias to the crtl_rms_stdio.c veneer instead of musl-POSIX.
• The final link adds --use LIBVMSRMS$SHR and stages LIBVMSRMS$SHR.EXE in OUTDIR alongside DECC$SHR/LIBOTS (the SYS$SHARE search-path set).
• Adds a toolchain-only CI leg (inside joint-e2e-alpha-crt0) that builds crtl_rms_test.c with the veneer opted in and asserts: veneer-wired log line, sys$create/open/connect/put/get/close bound to LIBVMSRMS$SHR inside DECC$SHR's own pass-2 build, zero deferred/undef/muldef on the final port-image link, EM_ALPHA/ET_DYN, and the port image's own decc$fopen import binding to that same veneer-wired DECC$SHR producer.
• Default (var unset) path is unchanged — the real-executive activation gates (run-module-gp-activation-alpha.sh's gate/crtl-rms-gate/mf-gate) never set the new var, so they stay on the plain DECC$SHR path. The runtime write-to-ODS-2 proof needs the LLP64 width fix (vms-1fc) and is rung 4 (vms-f49) — out of scope here.

Verification (local, docker + host LINK.EXE, ovmx-cross-alpha-vms:latest)

• Default build: byte-identical to before — zero UNDEF/MULDEF/DEFERRED, same staged files.
• JOINT_CRTL_RMS_VENEER=1 JOINT_MAIN=crtl_rms_test.c: DECC$SHR pass 2 logs mk_decc_shr: CRTL->RMS stdio veneer wired: decc$fopen/fwrite/fread/fclose -> ovmx_crtl_* (--use .../LIBVMSRMS$SHR.EXE) and binds sys$create/open/connect/put/get/close to LIBVMSRMS$SHR.EXE; the final joint_e2e.exe link (post-crt0) is zero deferred/undef/muldef, %LINK-S-CREATED, .../joint_e2e.exe: EVAX/Alpha ET_DYN, readelf shows Machine: Alpha / Type: DYN; the image's own decc$fopen import binds to the veneer-wired DECC$SHR.EXE producer.

Test plan

• bash -n syntax check on the modified script
• Local default build reproduces the pre-existing zero-deferred link byte-for-byte
• Local JOINT_CRTL_RMS_VENEER=1 build produces the veneer-wiring + sys$* binding + zero-deferred/EM_ALPHA/ET_DYN evidence
• Extracted new CI gate script run standalone against the local build output — passes
• CI green-by-SHA (pending — will report once checks complete)

🤖 Generated with Claude Code

https://claude.ai/code/session_01FJZf62TMXxvy6fXzFQYfLQ