register openkal-musl 0.19.0 (#453)

* register openkal-musl 0.19.0

`bits/setjmp.h` --- the INSTALLED header that sizes `jmp_buf` by the target's
calling convention --- reads `__MCPP_TARGET_WINDOWS__`, mcpp's own name for
the fact, and keeps `|| defined(__CYGWIN__)` beside it.

TWO OPERANDS COVER EVERY ENGINE AND THE ORDER OF RELEASES DOES NOT MATTER. An
engine up to and including 2026.9.21.1 defines the borrowed name, which
answers; the release that withdraws it defines mcpp's own, which answers
instead. There is no engine that defines neither, so this header has no flag
day.

The borrowed name was costing four members of the compatibility measurement,
each reading `__CYGWIN__` as "Win32 is available" and reaching
`#include <windows.h>`. Withdrawing it from the engine requires this release
to be PUBLISHED FIRST: measured on the engine branch that withdraws it,
building an openkal program for `x86_64-windows-gnu` against the published
0.18.0 fails on libunwind's two `static_assert`s.

No source of musl itself changed. Registration only; nothing is re-pinned
onto it by this change.

* the version goes into all three platform tables

`Lint platform version parity` is the check that caught it: the descriptor
carries `linux`, `macosx\' and `windows` tables and a version registered in
one of them is a package that resolves on one host and not on the others.
27 versions in each.

Author: Sunrisepeak

pkgs/o/openkal-musl.lua

@@ -21,6 +21,13 @@
 -- It also moves the implementation pins to openkal-linux 0.15.0 and
 -- openkal-windows 0.10.0. No source changed.
 --
+-- 0.19.0 reads `__MCPP_TARGET_WINDOWS__` in `bits/setjmp.h`, the INSTALLED
+-- header that sizes `jmp_buf` by the target's calling convention, keeping
+-- `|| defined(__CYGWIN__)` beside it. Two operands cover every engine and the
+-- order of releases does not matter: mcpp up to 2026.9.21.1 defines the
+-- borrowed name, the release that withdraws it defines mcpp's own, and no
+-- engine defines neither. No source of musl itself changed.
+--
 -- IT ASKS NOTHING OF `index.toml`'s `min_mcpp`, AND THAT WAS MEASURED. mcpp
 -- ignores a top-level table it does not know and refuses an unknown MEMBER of
 -- a table it does know, so the first spelling of this table --- `[c-abi]`.`absent`
@@ -45,6 +52,13 @@ package = {
 
     xpm = {
         linux = {
+            ["0.19.0"] = {
+                url    = {
+                    GLOBAL = "https://github.com/mcpplibs/openkal-musl/archive/refs/tags/0.19.0.tar.gz",
+                    CN     = "https://gitcode.com/mcpp-res/openkal-musl/releases/download/0.19.0/openkal-musl-0.19.0.tar.gz",
+                },
+                sha256 = "a7ff6615a9111ab829dfc175154384b6bc743b4b1f936c0fca22e6cabed4a516",
+            },
             ["0.18.0"] = {
                 url    = {
                     GLOBAL = "https://github.com/mcpplibs/openkal-musl/archive/refs/tags/0.18.0.tar.gz",
@@ -229,6 +243,13 @@ package = {
             },
         },
         macosx = {
+            ["0.19.0"] = {
+                url    = {
+                    GLOBAL = "https://github.com/mcpplibs/openkal-musl/archive/refs/tags/0.19.0.tar.gz",
+                    CN     = "https://gitcode.com/mcpp-res/openkal-musl/releases/download/0.19.0/openkal-musl-0.19.0.tar.gz",
+                },
+                sha256 = "a7ff6615a9111ab829dfc175154384b6bc743b4b1f936c0fca22e6cabed4a516",
+            },
             ["0.18.0"] = {
                 url    = {
                     GLOBAL = "https://github.com/mcpplibs/openkal-musl/archive/refs/tags/0.18.0.tar.gz",
@@ -413,6 +434,13 @@ package = {
             },
         },
         windows = {
+            ["0.19.0"] = {
+                url    = {
+                    GLOBAL = "https://github.com/mcpplibs/openkal-musl/archive/refs/tags/0.19.0.tar.gz",
+                    CN     = "https://gitcode.com/mcpp-res/openkal-musl/releases/download/0.19.0/openkal-musl-0.19.0.tar.gz",
+                },
+                sha256 = "a7ff6615a9111ab829dfc175154384b6bc743b4b1f936c0fca22e6cabed4a516",
+            },
             ["0.18.0"] = {
                 url    = {
                     GLOBAL = "https://github.com/mcpplibs/openkal-musl/archive/refs/tags/0.18.0.tar.gz",