LGTM.com - false positive - Java implicit cast in compound assignment for constants

**Description of the false positive**
The query `java/implicit-cast-in-compound-assignment` incorrectly flags compound statements with numeric literals within the value range of the target type. E.g.:
```
byte b = 1;
b *= 10; // Incorrectly flagged even though it is safe
```

Side note: Literals which exceed the value range should probably be even flagged as error (instead of warning):
```
byte b = 1;
b += 0xFF; // Exceeds 127, but is still in unsigned value range, might be intended: Ok
b += 256; // Very likely not intended: Error
```

Also why doesn't `java/implicit-cast-in-compound-assignment` cover all (arithmetic) compound assignments instead of only addition and multiplication?

**URL to the alert on the project page on LGTM.com**
https://lgtm.com/projects/g/apache/hive/snapshot/48856d424acd0be5fd4e911bbdabd9483a6fb39e/files/ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDFMaskFirstN.java?sort=name&dir=ASC&mode=heatmap#x348d57efee59c05:1