Fix type inference for static equals methods (and others found on java.lang.Object)

Method call `Chars.equals` showing as unknown (underlined) and hover shows javadoc for `Object.equals`.
```groovy
class Chars {
  static boolean equals(char[] a, char[] b) {
  }
  static void main(char[] x, char[] y) {
    if (Chars.equals(x, y)) {
    }
  }
}
```