Document PHP >= 7.2 build options

Author: sgolemon

config.env.default

@@ -15,3 +15,12 @@ export SSH_KEY="YOUR_KEY_FILE"
 
 # Define this to 1 to skip the final "git push origin" step
 #export DRY_RUN=1
+
+# Log the output of ./configure to the named file (>= PHP-7.2)
+#export CONFIG_LOG_FILE=/php-build/config.log
+
+# Log the output of make -j2 to the named file (>= PHP-7.2)
+#export MAKE_LOG_FILE=/php-build/make.log
+
+# Use N jobs (cpus) for PHP build (>= PHP-7.2)
+#export MAKE_JOBS=2