[Bug target/104323] New: [12 Regression] PCH (and maybe GC) of rs6000 builtins broken

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104323

            Bug ID: 104323
           Summary: [12 Regression] PCH (and maybe GC) of rs6000 builtins
                    broken
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
  Target Milestone: ---

echo '#include <altivec.h>' > mytest.h
./xgcc -B ./ -c mytest.h -o mytest.h.gch -isystem include/
cat > mytest.c <<\EOF
#include "mytest.h"

typedef __attribute__((altivec(vector__))) signed char scvec_t;

scvec_t
foo (scvec_t x, scvec_t y)
{
  return __builtin_vec_and (x, y);
}
EOF
./xgcc -B ./ -S mytest.c -freport-bug

xgcc: internal compiler error: Segmentation fault signal terminated program cc1
Please submit a full bug report, with preprocessed source.
See <https://gcc.gnu.org/bugs/> for instructions.

While the generated rs6000-builtins.h has some GTY markup:
extern GTY(()) tree rs6000_builtin_decls[RS6000_OVLD_MAX];
and
struct GTY((user)) bifdata
and
struct GTY((user)) ovlddata
and
extern GTY(()) tree bi_ftype_st;
extern GTY(()) tree bv16qi_ftype_bv16qi;
extern GTY(()) tree bv16qi_ftype_bv16qi_bv16qi;
extern GTY(()) tree bv16qi_ftype_bv16qi_bv16qi_bv16qi;
etc.