Also set CC=cc, CXX=c++ on Mac OS by default as upstream

Reference:
https://github.com/nodejs/node/blob/1bd871655a8b76fa3be1e3c6c325efa74c86fcd9/configure#L16-L17

Author: PeterDaveHello

nvm.sh

@@ -1848,12 +1848,22 @@ nvm_install_source() {
 
   local make
   make='make'
-  if [ "${NVM_OS}" = 'freebsd' ]; then
-    make='gmake'
-    [ -z "${CXX-}" ] && MAKE_CXX='CC=cc CXX=c++'
-  elif [ "${NVM_OS}" = 'aix' ]; then
-    make='gmake'
-  fi
+  case "${NVM_OS}" in
+    'freebsd')
+      make='gmake'
+      if [ -z "${CXX-}" ]; then
+        MAKE_CXX='CC=cc CXX=c++'
+      fi
+    ;;
+    'darwin')
+      if [ -z "${CXX-}" ]; then
+        MAKE_CXX='CC=cc CXX=c++'
+      fi
+    ;;
+    'aix')
+      make='gmake'
+    ;;
+  esac
   if nvm_has "clang++" && nvm_has "clang" && nvm_version_greater_than_or_equal_to nvm_clang_version 3.5 \
     && [ -z "${CC-}" ] && [ -z "${CXX-}" ] ; then
     nvm_echo "Clang v3.5+ detected! Use Clang as c/c++ compiler!"