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
*/
    @Override
    public void visitNewObj(ENewObj userNewObjNode, SemanticScope semanticScope) {
        String canonicalTypeName = userNewObjNode.getCanonicalTypeName();
        List<AExpression> userArgumentNodes = userNewObjNode.getArgumentNodes();
        int userArgumentsSize = userArgumentNodes.size();
        if (semanticScope.getCondition(userNewObjNode, Write.class)) {
            throw userNewObjNode.createError(
                new IllegalArgumentException(
                    "invalid assignment cannot assign a value to new object with constructor "
                        + "["
                        + canonicalTypeName
                        + "/"
                        + userArgumentsSize
                        + "]"
                )
            );
        }
        ScriptScope scriptScope = semanticScope.getScriptScope();
        Class<?> valueType = scriptScope.getPainlessLookup().canonicalTypeNameToType(canonicalTypeName);
        if (valueType == null) {
            throw userNewObjNode.createError(new IllegalArgumentException("Not a type [" + canonicalTypeName + "]."));
        }
        PainlessConstructor constructor = scriptScope.getPainlessLookup().lookupPainlessConstructor(valueType, userArgumentsSize);
        if (constructor == null) {
            throw userNewObjNode.createError(
                new IllegalArgumentException(
                    "constructor [" + typeToCanonicalTypeName(valueType) + ", <init>/" + userArgumentsSize + "] not found"
                )
            );