revert upstream commit 5a3ee43e1b6e "Stop building packages built by gcc-15"

debian/rules.defs

@@ -570,7 +570,7 @@ endif
 # gcc versions (fixincludes, ...)
 with_common_pkgs := yes
 # ... and some libraries, which do not change (libgcc1, libssp0).
-#with_common_libs := yes
+with_common_libs := yes
 # XXX: should with_common_libs be "yes" only if this is the default compiler
 # version on the targeted arch?
 
@@ -795,9 +795,9 @@ ifneq (,$(findstring build-cross, $(build_type)))
 endif
 
 ifeq ($(with_jit),yes)
-    #ifeq ($(with_common_libs),yes)
+    ifeq ($(with_common_libs),yes)
       with_libgccjit := yes
-    #endif
+    endif
 endif
 
 nvptx_archs := amd64 arm64 ppc64el
@@ -1242,9 +1242,9 @@ ifeq ($(with_m2),yes)
   ifeq ($(with_dev),yes)
     with_m2dev := yes
   endif
-  #ifeq ($(with_common_libs),yes)
+  ifeq ($(with_common_libs),yes)
     with_libgm2 := yes
-  #endif
+  endif
   enabled_languages += m2
 endif