Fix and re-enable test-api/InitializeAndDispose.

src/assembler.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 919 matching lines @@
       math_exp_log_table_array[i] = mantissa;
     }
 
     math_exp_data_initialized = true;
   }
 }
 
 
 void ExternalReference::TearDownMathExpData() {
   delete[] math_exp_constants_array;
+  math_exp_constants_array = NULL;
   delete[] math_exp_log_table_array;
+  math_exp_log_table_array = NULL;
   delete math_exp_data_mutex;
+  math_exp_data_mutex = NULL;
 }
 
 
 ExternalReference::ExternalReference(Builtins::CFunctionId id, Isolate* isolate)
   : address_(Redirect(isolate, Builtins::c_function_address(id))) {}
 
 
 ExternalReference::ExternalReference(
     ApiFunction* fun,
     Type type = ExternalReference::BUILTIN_CALL,
@@ skipping 644 matching lines @@
       r2 = r2 - ad;
     }
     delta = ad - r2;
   } while (q1 < delta || (q1 == delta && r1 == 0));
   int32_t mul = static_cast<int32_t>(q2 + 1);
   multiplier_ = (d < 0) ? -mul : mul;
   shift_ = p - 32;
 }
 
 } }  // namespace v8::internal