[Bug] "cc" is used instead of ${CC} on Apple platforms for linking

[Veence]

The standard configure file has this line for SHLIB_LD for MacOS (Darwin) platforms:

SHLIB_LD="cc -dynamiclib -compatibility_version \${GRASS_VERSION_MAJOR}.\${GRASS_VERSION_MINOR} -current_version \${GRASS_VERSION_MAJOR}.\${GRASS_VERSION_MINOR} -install_name \${INST_DIR}/lib/lib\${LIB_NAME}\${SHLIB_SUFFIX}"

And this causes links to be invoked with "cc" instead of whatever compiler has been selected to compile Grass. I have no idea why this is so, but this "cc" should be changed into ${CC} as it is done in Linux/FreeBSD cases.

--- configure.init      2020-05-11 09:53:05.000000000 +0200
+++ configure   2020-05-11 09:54:35.000000000 +0200
@@ -1541,7 +1541,7 @@
        *-apple-darwin*)
            SHLIB_CFLAGS="-fno-common"
            SHLIB_SUFFIX=".dylib"
-           SHLIB_LD="cc -dynamiclib -compatibility_version \${GRASS_VERSION_MAJOR}.\${GRASS_VERSION_MINOR} -current_version \${GRASS_VERSION_MAJOR}.\${GRASS_VERSION_MINOR} -install_name \${INST_DIR}/lib/lib\${LIB_NAME}\${SHLIB_SUFFIX}"
+           SHLIB_LD="${CC} -dynamiclib -compatibility_version \${GRASS_VERSION_MAJOR}.\${GRASS_VERSION_MINOR} -current_version \${GRASS_VERSION_MAJOR}.\${GRASS_VERSION_MINOR} -install_name \${INST_DIR}/lib/lib\${LIB_NAME}\${SHLIB_SUFFIX}"
            LD_LIBRARY_PATH_VAR="DYLD_LIBRARY_PATH"
            ;;
        *-sun-solaris*)