[Bug tree-optimization/83992] wrong debug info: wrong NOTE_INSN_BLOCK_BEG placement causes TestCrashDumpsAllThreads gotools testcase failure

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83992

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Corresponding C testcase would be something like:
static inline void
foo (void)
{
  int j;
  while (1)
    for (j = 0; j < 0x7fffffff; ++j)
      ;
}

int
main ()
{
  foo ();
}
at -O2 -g {,-fno-var-tracking-assignments} {,-gno-statement-frontiers}