Support parsing of class signatures for inner classes inside Scala singleton objects.

Example: Let "MyClass" be a Scala singleton Object, and "Inner" be an inner
class inside MyClass.

  Signature: Lcom/prod/MyClass$$Inner"
  Type Name: com.prod.MyClass$.Inner  (after this CL)
             com.prod.MyClass..Inner  (before this CL)

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=159759658

Author: emrekultursay

src/agent/type_util.cc

@@ -437,8 +437,16 @@ string TypeNameFromJObjectSignature(string object_signature) {
     } else if (ch == '$') {
       if (source + 1 == object_signature.end()) {
         ch = '.';
-      } else if (!isdigit(*(source + 1)) && *(source + 1) != ';') {
-        // Neither an anonymous class, nor a Scala singleton.
+      } else if (*(source + 1) == '$') {
+        // Inner class inside Scala singleton. Pass the $ character as is.
+        // E.g., "Lcom/prod/MyClassObject$$anonfun$1"
+      } else if (isdigit(*(source + 1))) {
+        // Anonymous class. Pass the $ character as is.
+        // E.g., "Lcom/prod/MyClass$1;"
+      } else if (*(source + 1) == ';') {
+        // Scala singleton object. Pass the $ character as is.
+        // E.g., "Lcom/prod/MyClassObject$;"
+      } else {
         ch = '.';
       }
     }