Fix the unintelligible IsValidClassName API by breaking it into three.

There are only three of the four possibilities you actually want, so we may as
well just call them by name.

Change-Id: I481d91d98d6d47430f1972891fa81a61c57ad331
diff --git a/src/java_lang_Class.cc b/src/java_lang_Class.cc
index eccf977..1700ce1 100644
--- a/src/java_lang_Class.cc
+++ b/src/java_lang_Class.cc
@@ -38,7 +38,7 @@
   // We need to validate and convert the name (from x.y.z to x/y/z).  This
   // is especially handy for array types, since we want to avoid
   // auto-generating bogus array classes.
-  if (!IsValidClassName(name.c_str(), true, true)) {
+  if (!IsValidBinaryClassName(name.c_str())) {
     Thread::Current()->ThrowNewExceptionF("Ljava/lang/ClassNotFoundException;",
         "Invalid name: %s", name.c_str());
     return NULL;