[Bug debug/87440] GCC creates debug that confuses gdb

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87440

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 44754
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44754&action=edit
not working patch

Simply merging the single subblock of an inline block runs afoul several
issues:
- dead block removal can make it multiple subblocks (the assert in the patch
fires)
- dead block removal can make us elide "real" scopes which isn't a problem for
live variables but it will hide optimized out ones.

So one could call the block eliding premature optimization...  but it's
somewhat hardwired as we do not emit begin/end labels for that block.