fix x86_64 fe[gs]etround, analogous to nsz's x86 changes
[musl] / crt /
drwxr-xr-x   ..
drwxr-xr-x - arm
-rw-r--r-- 0 crt1.c
-rw-r--r-- 0 crti.c
-rw-r--r-- 0 crtn.c
drwxr-xr-x - i386
drwxr-xr-x - x86_64