	MacOS (darwin) compilation/installation instructions
	----------------------------------------------------

The procedure is standard and detailed in ../INSTALL file.

Under MacOS, by default, gcc is a shorthand for clang (both compilers
are widely compatible).

It is however possible to real use gcc (gcc can be installed with
homebrew).  NB: gcc provides global register variables (clang does not
(yet?) support them).

It is possible to set PATH so that gcc is selected (before clang). In
that case simply use: ./configure

If the binary is not called gcc (e.g. gcc-10) or if it is not in the
PATH and needs an absolute path, set the CC variable before
./configure. Examples:

CC=gcc-10 ./configure
or
CC=/opt/homebrew/bin/gcc-10 ./configure

This will use gcc for C code and linkage. Assembly code will be done
by clang/llvm (this should work as both assemblers are compatible).

To even force to use another assembler, set the AS variable before
configure.  It is even possible to use the gcc assembler (do not
forget to pass -c) with:

CC=gcc-10 AS='gcc-10 -c' ./configure

