[Bug target/87532] bad results from vec_extract(unsigned char, foo) dependent upon function inline

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87532

--- Comment #7 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
To be absolutely clear, code like 

unsigned int get_auto_n_int ( vector unsigned int a, int n) {   return     
__builtin_vec_extract (a, n); }

is invalid.  The second argument must be constant.  This was not properly
documented in the ABI appendix, but should have been.