"Floating point" refers to both `double` and `float`, and is also used by
the JLS in this way. Therefore the old CodeQL class name for `float` literals
was misleading.
I introduce AnyEqualsExpr for either reference or value equality and AnyEqualityTest for the same concept including not-equals operators, and use them wherever the written QL clearly doesn't care about the difference between reference and value comparison, typically because it is concerned with testing against null or against a primitive constant.
We might want to unify some of these in future, but doing that
correctly is easier than splitting them up correctly, so I've given each
one its own QL class for now.
I am not familiar with many of the libraries/queries that use CastExpr.
I've briefly looked at them and updated them in a way that looks
superficially reasonable, but some of the uses will probably want to be
refined later.
As mentioned by aschackmull during review, StatementExpression as defined
by the JLS only lists possible types of expressions, it does _not_ specify
that their value is discarded. Therefore, for example any method call could
be considered a StatementExpression.
The name ValueDiscardingExpr was chosen as replacement because the JLS uses
the phrase "if the expression has a value, the value is discarded" multiple
times.
Raised in https://github.com/github/codeql/issues/7601, this is one of the only .ql files that has a security-severity score but not the tag "security", including many other queries that live outside the `Security/` subdirectory.
Besides this the only other files with this security-severity-but-no-security-tag combination are:
```
java/ql/src/Frameworks/JavaEE/EJB/EjbContainerInterference.ql
java/ql/src/Frameworks/JavaEE/EJB/EjbFileIO.ql
java/ql/src/Frameworks/JavaEE/EJB/EjbNative.ql
java/ql/src/Frameworks/JavaEE/EJB/EjbReflection.ql
java/ql/src/Frameworks/JavaEE/EJB/EjbSecurityConfiguration.ql
java/ql/src/Frameworks/JavaEE/EJB/EjbSerialization.ql
java/ql/src/Frameworks/JavaEE/EJB/EjbSetSocketOrUrlFactory.ql
```
Given their location I'm assuming these queries are disabled by default and likely shouldn't changed?
