[Bug driver/115368] Wrong order of gcc include paths on musl systems

[raj.khem at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115368

--- Comment #1 from Khem Raj <raj.khem at gmail dot com> ---
Created attachment 58366
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58366&action=edit
potential fix

This patch uses -idirafter instead of -iprefix when building for musl. This
fixes the issue as the search paths get adjusted and sysroot is searched before
gcc headers dir.