Apply the same filtering to -I paths as -L paths

Library/ENV/4.3/cc

@@ -134,10 +134,19 @@ class Cmd
       when /^-I(.+)?/
         # Support both "-Ifoo" (one argument) and "-I foo" (two arguments)
         path = $1.chuzzle || whittler.next
-        args << "-I#{path}" if iset.add?(path.cleanpath)
+        args << "-I#{path}" if keep?(path) and iset.add?(path.cleanpath)
       when /^-L(.+)?/
         path = $1.chuzzle || whittler.next
-        doit = case path.cleanpath
+        args << "-L#{path}" if keep?(path) and lset.add?(path.cleanpath)
+      else
+        args << arg
+      end
+    end
+    args
+  end
+
+  def keep? path
+    case path.cleanpath
     when %r{^#{Regexp.escape(brewfix)}}, %r{^#{Regexp.escape(brewtmp)}}
       # maybe homebrew is installed to /sw or /opt/brew
       true
@@ -146,13 +155,8 @@ class Cmd
     else
       true
     end
-        args << "-L#{path}" if doit and lset.add?(path.cleanpath)
-      else
-        args << arg
-      end
-    end
-    args
   end
+
   def cflags
     args = []