[Bug lto/57703] Assembler function definition moved to a different ltrans then call

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57703

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
This is just totally broken and not supportable with LTO.  We'd need to amend
toplevel asm syntax to list defined and used symbols, but that doesn't fix
existing uses.

The proper fix is to excempt these files from LTO or move those assembler
functions to separate TUs (preferably assembler TUs...).

Honza also had the idea of trying to parse the assembler string for
"obvious" symbol definitions / uses.