Minor: added @NotNull annotations from interfaces.

compiler/frontend/src/org/jetbrains/jet/lang/descriptors/ValueParameterDescriptor.java

@@ -39,6 +39,7 @@ public interface ValueParameterDescriptor extends VariableDescriptor, Annotated
     @NotNull
     JetType getType();
 
+    @NotNull
     @Override
     ValueParameterDescriptor getOriginal();
 

compiler/frontend/src/org/jetbrains/jet/lang/descriptors/VariableDescriptorImpl.java

@@ -51,6 +51,7 @@ public abstract class VariableDescriptorImpl extends DeclarationDescriptorImpl i
         super(containingDeclaration, annotations, name);
     }
 
+    @NotNull
     @Override
     public JetType getType() {
         return outType;