MIPS: NPE fix for sorting (joernio#813)

* NPE fix for sorting

Seems that i only have moved the NPE before

* Name ..

* try catch

joern-cli/frontends/ghidra2cpg/src/main/scala/io/joern/ghidra2cpg/Ghidra2Cpg.scala

@@ -174,7 +174,6 @@ class Ghidra2Cpg() {
           new ReturnEdgesPass(cpg).createAndApply()
         }
     }
-
     new TypesPass(cpg).createAndApply()
     new JumpPass(cpg, keyPoolIterator.next()).createAndApply()
     new LiteralPass(cpg, address2Literals, program, flatProgramAPI, keyPoolIterator.next()).createAndApply()
@@ -189,12 +188,15 @@ class Ghidra2Cpg() {
 }
 
 object Types {
-
   // Types will be added to the CPG as soon as everything
   // else is done
-  val types: ListBuffer[String] = ListBuffer[String]()
+  var types: mutable.SortedSet[String] = mutable.SortedSet[String]()
   def registerType(typeName: String): String = {
-    types += typeName
+    try {
+      types += typeName
+    } catch {
+      case e: Exception => println(s" Error adding type: $typeName")
+    }
     typeName
   }
 }

joern-cli/frontends/ghidra2cpg/src/main/scala/io/joern/ghidra2cpg/passes/TypesPass.scala

@@ -9,7 +9,7 @@ class TypesPass(cpg: Cpg) extends CpgPass(cpg) {
 
   override def run(): Iterator[DiffGraph] = {
     implicit val diffGraph: DiffGraph.Builder = DiffGraph.newBuilder
-    Types.types.sorted.distinct
+    Types.types
       .foreach { typ =>
         val typeNode =
           nodes.NewType().name(typ).fullName(typ).typeDeclFullName(typ)

joern-cli/frontends/ghidra2cpg/src/main/scala/io/joern/ghidra2cpg/passes/mips/MipsFunctionPass.scala

@@ -40,6 +40,9 @@ class MipsFunctionPass(currentProgram: Program,
           name = symbol.get.getName
         }
       }
+      if (name == null) {
+        name = input.getHigh.getSymbol.getName
+      }
       createIdentifier(name,
                        name,
                        index + 1,