signature help stops working after using a lambda

[puremourning]

I found this while implementing signature help in ycmd, and repro'd in visual studio code.

Steps to repro:

• Create SignatureHelp.java:

import java.util.function.Function;

public class SignatureHelp
{
  public SignatureHelp( String signature ) {
    this.test( (s) -> s );
//.   this.test(
  }
  public void test( Function<String,String> f ) {
  }
}

• uncomment this.test(, and re-type the (

Expected result:

• void test( Function<....> ) function is proposed

Actual result:

• No proposals

Corroloary:

• Requesting this.test( before the lambda works as expected.

[snjeza]

Related issue - #1039

[snjeza]

Fixed within #1063