Bug#1084955: llvm-toolchain-*: assembly code seems to depend on build cpu capabilities

[Matthias Klose]

Control: severity -1 serious
Control: tags -1 + moreinfo

clang doesn't have a good way to set the baseline for a build, nothing 
as easy as in GCC with --with-arch=<baseline>.

I did that for both the armel and armhf architectures (see the 
arm32-defaults.diff patch), but this is unchecked for any other release 
architectures, and obviously wrong for some architectures.

Please could you run (at least on amd64)

/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 --help

and look for the last lines like

Subdirectories of glibc-hwcaps directories, in priority order:
   x86-64-v4 (supported, searched)
   x86-64-v3 (supported, searched)
   x86-64-v2 (supported, searched)

on the machines where you saw that?