musl libc (http://musl-libc.org lack the non-standard <fpu_control.h>
header, which is used in src/os/linux/{i386,x86_64}/init.c files to
setup the floating point precision. This patch makes it use the
standard C <fenv.h> header instead.
Original patch at Felix Janda at
https://sourceforge.net/p/jamvm/patches/6/
Signed-off-by: Guo Li <uxgood.org@gmail.com>
