src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symbol.java

*** 2061,2071 ****
              return v.visitMethodSymbol(this, p);
          }
  
          @DefinedBy(Api.LANGUAGE_MODEL)
          public Type getReceiverType() {
!             return asType().getReceiverType();
          }
  
          @DefinedBy(Api.LANGUAGE_MODEL)
          public Type getReturnType() {
              return asType().getReturnType();
--- 2061,2072 ----
              return v.visitMethodSymbol(this, p);
          }
  
          @DefinedBy(Api.LANGUAGE_MODEL)
          public Type getReceiverType() {
!             Type result = asType().getReceiverType();
!             return (result == null) ? Type.noType : result;
          }
  
          @DefinedBy(Api.LANGUAGE_MODEL)
          public Type getReturnType() {
              return asType().getReturnType();