[Bug sanitizer/63927] AddressSanitizer painfully slow on ppc64

[kcc at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63927

--- Comment #4 from Kostya Serebryany <kcc at gcc dot gnu.org> ---
Why can't we use frame pointers on PPC? 
So far I have not seen any implementation of unwinder not based on FPs
that was fast enough for ASan. 
ASan unwinds the stack on every malloc/free and thus it is very sensitive to
the unwinder performance.