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
+ operation.symbol
                        + "] to the types "
                        + "["
                        + PainlessLookupUtility.typeToCanonicalTypeName(leftValueType)
                        + "] and "
                        + "["
                        + PainlessLookupUtility.typeToCanonicalTypeName(rightValueType)
                        + "]"
                )
            );
        }
        if ((operation == Operation.EQ || operation == Operation.EQR || operation == Operation.NE || operation == Operation.NER)
            && userLeftNode instanceof ENull
            && userRightNode instanceof ENull) {
            throw userCompNode.createError(new IllegalArgumentException("extraneous comparison of [null] constants"));
        }
        if (operation == Operation.EQR || operation == Operation.NER || promotedType != def.class) {
            semanticScope.putDecoration(userLeftNode, new TargetType(promotedType));
            semanticScope.putDecoration(userRightNode, new TargetType(promotedType));
            decorateWithCast(userLeftNode, semanticScope);
            decorateWithCast(userRightNode, semanticScope);
        }
        semanticScope.putDecoration(userCompNode, new ValueType(boolean.class));
        semanticScope.putDecoration(userCompNode, new ComparisonType(promotedType));
    }
    /**
     * Visits an explicit expression which handles an explicit cast.
     * Checks: type validation
     */
    @Override