[gcc r17-3332] toplevel: do not make libstdc++ configure wait for libgomp

https://gcc.gnu.org/g:bf2aada7d8a4f701365d260a56cb7669a6934c3e

commit r17-3332-gbf2aada7d8a4f701365d260a56cb7669a6934c3e
Author: Kyrylo Tkachov <[email protected]>
Date:   Tue Aug 11 09:58:40 2026 +0200

    toplevel: do not make libstdc++ configure wait for libgomp
    
    libstdc++'s configure was made to depend on libgomp's configure by
    r0-83445-g6d3b5aea0bf4c9 ("configure.ac (TOPLEVEL_CONFIGURE_ARGUMENTS): Move
    libgomp before libstdc++.", 2007-09-20), when GLIBCXX_ENABLE_PARALLEL decided
    whether to enable parallel mode by looking for a configured libgomp/omp.h on
    disk:
    
      if test -f $glibcxx_builddir/../libgomp/omp.h; then
    
    r0-98141-gaae29963cf81dd ("PR libstdc++/36101, PR libstdc++/42813",
    2010-01-22) replaced that with
    
      if echo " ${TARGET_CONFIGDIRS} " | grep " libgomp " > /dev/null 2>&1 ; then
    
    so the test now reads a string the top level passes in, and nothing has to
    exist on disk by then.  The comment above it still describes the old
    behaviour, which is what makes the edge look necessary.
    
    Remove it.  The build time dependency, all-target-libstdc++-v3 on
    configure-target-libgomp, stays, since the parallel mode headers do include
    omp.h when they are compiled.
    
    This shortens the chain in front of libstdc++, which is the last thing to
    finish in every bootstrap stage.
    
    Bootstrapped on aarch64-none-linux-gnu.
    
    ChangeLog:
    
            * Makefile.def (dependencies): Remove the configure-target-libstdc++-v3
            on configure-target-libgomp dependency.
            * Makefile.in: Regenerate.
    
    Signed-off-by: Kyrylo Tkachov <[email protected]>

Diff:
---
 Makefile.def |  1 -
 Makefile.in  | 10 ----------
 2 files changed, 11 deletions(-)

diff --git a/Makefile.def b/Makefile.def
index 549763de837a..6098de2904de 100644
--- a/Makefile.def
+++ b/Makefile.def
@@ -679,7 +679,6 @@ dependencies = { module=configure-target-libphobos; on=configure-target-zlib; };
 dependencies = { module=all-target-libphobos; on=all-target-libbacktrace; };
 dependencies = { module=all-target-libphobos; on=all-target-zlib; };
 dependencies = { module=all-target-libphobos; on=all-target-libatomic; };
-dependencies = { module=configure-target-libstdc++-v3; on=configure-target-libgomp; };
 dependencies = { module=configure-target-libsanitizer; on=all-target-libstdc++-v3; };
 dependencies = { module=configure-target-libvtv; on=all-target-libstdc++-v3; };
 dependencies = { module=configure-target-libgrust; on=all-target-libstdc++-v3; };
diff --git a/Makefile.in b/Makefile.in
index 5cca69c3f523..31eecec49caa 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -69768,16 +69768,6 @@ all-stagetrain-target-libphobos: maybe-all-stagetrain-target-libatomic
 all-stagefeedback-target-libphobos: maybe-all-stagefeedback-target-libatomic
 all-stageautoprofile-target-libphobos: maybe-all-stageautoprofile-target-libatomic
 all-stageautofeedback-target-libphobos: maybe-all-stageautofeedback-target-libatomic
-configure-target-libstdc++-v3: maybe-configure-target-libgomp
-configure-stage1-target-libstdc++-v3: maybe-configure-stage1-target-libgomp
-configure-stage2-target-libstdc++-v3: maybe-configure-stage2-target-libgomp
-configure-stage3-target-libstdc++-v3: maybe-configure-stage3-target-libgomp
-configure-stage4-target-libstdc++-v3: maybe-configure-stage4-target-libgomp
-configure-stageprofile-target-libstdc++-v3: maybe-configure-stageprofile-target-libgomp
-configure-stagetrain-target-libstdc++-v3: maybe-configure-stagetrain-target-libgomp
-configure-stagefeedback-target-libstdc++-v3: maybe-configure-stagefeedback-target-libgomp
-configure-stageautoprofile-target-libstdc++-v3: maybe-configure-stageautoprofile-target-libgomp
-configure-stageautofeedback-target-libstdc++-v3: maybe-configure-stageautofeedback-target-libgomp
 configure-target-libsanitizer: maybe-all-target-libstdc++-v3
 configure-stage1-target-libsanitizer: maybe-all-stage1-target-libstdc++-v3
 configure-stage2-target-libsanitizer: maybe-all-stage2-target-libstdc++-v3