define and use $CCCOM variable for CC command

lib/rscons/builders/cc.rb

@@ -2,10 +2,11 @@ module Rscons
   class CC < Builder
     VARIABLE_DEFAULTS = {
       'CC' => 'gcc',
-      'CFLAGS' => ['-c'],
+      'CFLAGS' => [],
       'CPPFLAGS' => [],
       'OBJSUFFIX' => '.o',
       'CEXTS' => ['.c'],
+      'CCCOM' => ['$CC', '-c', '-o', '$TARGET', '$CPPFLAGS', '$CFLAGS', '$SOURCES']
     }
 
     def self.produces?(env, suffix)
@@ -16,18 +17,11 @@ module Rscons
       raise "String expected, not #{source.inspect}" unless source.is_a?(String)
       o_file = "#{env.stem(source)}#{env['OBJSUFFIX']}"
       unless Cache.open.up_to_date?(target, [source])
-        command = [
-          env['CC'],
-          *env['CPPFLAGS'],
-          *env['CFLAGS'],
-          '-o', o_file,
-          source
-        ]
         vars = {
           'TARGET' => o_file,
           'SOURCES' => source,
         }
-        env.execute("CC #{o_file}", command, vars)
+        env.execute("CC #{o_file}", env['CCCOM'], vars)
         Cache.open.register_build(target, [source])
       end
       o_file