Store some build-specific environment variables in config.nice.

acinclude.m4

@@ -305,8 +305,15 @@ AC_DEFUN(PHP_CONFIG_NICE,[
 
 EOF
 
+  for var in CFLAGS CXXFLAGS CPPFLAGS LDFLAGS LIBS CC CXX; do
+    eval val=\$$var
+    if test -n "$val"; then
+      echo "$var='$val' \\" >> $1
+    fi
+  done
+
   for arg in [$]0 "[$]@"; do
-    echo "\"[$]arg\" \\" >> $1
+    echo "'[$]arg' \\" >> $1
   done
   echo '"[$]@"' >> $1
   chmod +x $1