Change --hydrogen-filter to allow specifying a negative filter for optimized functions.

src/compiler.cc

Index: src/compiler.cc
===================================================================
--- src/compiler.cc	(revision 10973)
+++ src/compiler.cc	(working copy)
@@ -244,12 +244,15 @@
   }
 
   // Take --hydrogen-filter into account.
-  Vector<const char> filter = CStrVector(FLAG_hydrogen_filter);
   Handle<String> name = info->function()->debug_name();
-  bool match = filter.is_empty() || name->IsEqualTo(filter);
-  if (!match) {
-    info->SetCode(code);
-    return true;
+  if (*FLAG_hydrogen_filter != '\0') {
+    Vector<const char> filter = CStrVector(FLAG_hydrogen_filter);
+    if ((filter[0] == '-'
+         && name->IsEqualTo(filter.SubVector(1, filter.length())))
+        || (filter[0] != '-' && !name->IsEqualTo(filter))) {
+      info->SetCode(code);
+      return true;
+    }
   }
 
   // Recompile the unoptimized version of the code if the current version