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
* Checks: type validation
     */
    @Override
    public void visitInstanceof(EInstanceof userInstanceofNode, SemanticScope semanticScope) {
        String canonicalTypeName = userInstanceofNode.getCanonicalTypeName();
        if (semanticScope.getCondition(userInstanceofNode, Write.class)) {
            throw userInstanceofNode.createError(
                new IllegalArgumentException(
                    "invalid assignment: cannot assign a value to instanceof with target type [" + canonicalTypeName + "]"
                )
            );
        }
        if (semanticScope.getCondition(userInstanceofNode, Read.class) == false) {
            throw userInstanceofNode.createError(
                new IllegalArgumentException(
                    "not a statement: result not used from instanceof with target type [" + canonicalTypeName + "]"
                )
            );
        }
        Class<?> instanceType = semanticScope.getScriptScope().getPainlessLookup().canonicalTypeNameToType(canonicalTypeName);
        if (instanceType == null) {
            throw userInstanceofNode.createError(new IllegalArgumentException("Not a type [" + canonicalTypeName + "]."));
        }
        AExpression userExpressionNode = userInstanceofNode.getExpressionNode();
        semanticScope.setCondition(userExpressionNode, Read.class);
        checkedVisit(userExpressionNode, semanticScope);
        semanticScope.putDecoration(userInstanceofNode, new ValueType(boolean.class));
        semanticScope.putDecoration(userInstanceofNode, new InstanceType(instanceType));
    }
    /**