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
throw userCallLocalNode.createError(
                                    new IllegalArgumentException(
                                        "Unknown call [" + methodName + "] with [" + userArgumentsSize + "] arguments."
                                    )
                                );
                            }
                        }
                    }
                }
            }
        }
        List<Class<?>> typeParameters;
        if (localFunction != null) {
            semanticScope.setUsesInstanceMethod();
            semanticScope.putDecoration(userCallLocalNode, new StandardLocalFunction(localFunction));
            typeParameters = new ArrayList<>(localFunction.getTypeParameters());
            valueType = localFunction.getReturnType();
        } else if (thisMethod != null) {
            semanticScope.setUsesInstanceMethod();
            semanticScope.putDecoration(userCallLocalNode, new ThisPainlessMethod(thisMethod));
            scriptScope.markNonDeterministic(thisMethod.annotations().containsKey(NonDeterministicAnnotation.class));
            typeParameters = new ArrayList<>(thisMethod.typeParameters());
            valueType = thisMethod.returnType();
        } else if (importedMethod != null) {
            semanticScope.putDecoration(userCallLocalNode, new StandardPainlessMethod(importedMethod));
            scriptScope.markNonDeterministic(importedMethod.annotations().containsKey(NonDeterministicAnnotation.class));
            typeParameters = new ArrayList<>(importedMethod.typeParameters());
            valueType = importedMethod.returnType();
        } else if (classBinding != null) {
            semanticScope.putDecoration(userCallLocalNode, new StandardPainlessClassBinding(classBinding));