If a hex literal has an 'd' of 'f' in it, such as '0xf' or '0xd', the compiler fails with illegal tree structure.

The other hex literals work.  The issue is probably related to using `f` and `d` in float and double literals.

```
    public void testHexCollisionDouble() {
        assertEquals(13, exec("return 0xd"));
    }

    public void testHexCollisionFloat() {
        assertEquals(15, exec("return 0xf"));
    }

    public void testHex() throws Exception {
        for (int i = 0; i <= 15; i++) {
            String hex = Integer.toHexString(i);
            if ("d".equals(hex) || "f".equals(hex)) {
                continue;
            }
            assertEquals(i, exec("return 0x" + hex));
            assertEquals(i, exec("return 0x" + hex.toUpperCase(Locale.ROOT)));
            assertEquals(i, exec("return 0X" + hex));
            assertEquals(i, exec("return 0X" + hex.toUpperCase(Locale.ROOT)));
        }
    }
```
modules/lang-painless/src/main/java/org/elasticsearch/painless/phase/DefaultSemanticAnalysisPhase.java
new IllegalArgumentException("Argument(s) cannot be of [void] type when calling method [" + methodName + "].")
                    );
                }
            }
            TargetType targetType = userCallNode.isNullSafe() ? null : semanticScope.getDecoration(userCallNode, TargetType.class);
            valueType = targetType == null || semanticScope.getCondition(userCallNode, Explicit.class)
                ? def.class
                : targetType.targetType();
            semanticScope.setCondition(userCallNode, DynamicInvocation.class);
        } else {
            Objects.requireNonNull(method);
            semanticScope.getScriptScope().markNonDeterministic(method.annotations().containsKey(NonDeterministicAnnotation.class));
            for (int argument = 0; argument < userArgumentsSize; ++argument) {
                AExpression userArgumentNode = userArgumentNodes.get(argument);
                semanticScope.setCondition(userArgumentNode, Read.class);
                semanticScope.putDecoration(userArgumentNode, new TargetType(method.typeParameters().get(argument)));
                semanticScope.setCondition(userArgumentNode, Internal.class);
                checkedVisit(userArgumentNode, semanticScope);
                decorateWithCast(userArgumentNode, semanticScope);
            }
            semanticScope.putDecoration(userCallNode, new StandardPainlessMethod(method));
            valueType = method.returnType();
        }
        if (userCallNode.isNullSafe() && valueType.isPrimitive()) {
            throw new IllegalArgumentException("Result of null safe operator must be nullable");
        }
        semanticScope.putDecoration(userCallNode, new ValueType(valueType));
    }
}