Improvements to C/C++ analysis

The following changes in version 1.23 affect C/C++ analysis in all applications.

General improvements

Query	Tags	Purpose
Hard-coded Japanese era start date (`cpp/japanese-era/exact-era-date`)	reliability, japanese-era	This query is a combination of two old queries that were identical in purpose but separate as an implementation detail. This new query replaces Hard-coded Japanese era start date in call (`cpp/japanese-era/constructor-or-method-with-exact-era-date`) and Hard-coded Japanese era start date in struct (`cpp/japanese-era/struct-with-exact-era-date`).

Query	Expected impact	Change
Query name (`query id`)	Expected impact	Message.
Hard-coded Japanese era start date in call (`cpp/japanese-era/constructor-or-method-with-exact-era-date`)	Deprecated	This query has been deprecated. Use the new combined query Hard-coded Japanese era start date (`cpp/japanese-era/exact-era-date`) instead.
Hard-coded Japanese era start date in struct (`cpp/japanese-era/struct-with-exact-era-date`)	Deprecated	This query has been deprecated. Use the new combined query Hard-coded Japanese era start date (`cpp/japanese-era/exact-era-date`) instead.
Hard-coded Japanese era start date (`cpp/japanese-era/exact-era-date`)	More correct results	This query now checks for the beginning date of the Reiwa era (1st May 2019).
Sign check of bitwise operation (`cpp/bitwise-sign-check`)	Fewer false positive results	Results involving `>=` or `<=` are no longer reported.
Too few arguments to formatting function (`cpp/wrong-number-format-arguments`)	Fewer false positive results	Fixed false positives resulting from mistmatching declarations of a formatting function.
Too many arguments to formatting function (`cpp/too-many-format-arguments`)	Fewer false positive results	Fixed false positives resulting from mistmatching declarations of a formatting function.
Unclear comparison precedence (`cpp/comparison-precedence`)	Fewer false positive results	False positives involving template classes and functions have been fixed.

The data-flow library has been extended with a new feature to aid debugging. Instead of specifying isSink(Node n) { any() } on a configuration to explore the possible flow from a source, it is recommended to use the new Configuration::hasPartialFlow predicate, as this gives a more complete picture of the partial flow paths from a given source. The feature is disabled by default and can be enabled for individual configurations by overriding int explorationLimit().
The data-flow library now allows flow through the address-of operator (&).
The DataFlow::DefinitionByReferenceNode class now considers f(x) to be a definition of x when x is a variable of pointer type. It no longer considers deep paths such as f(&x.myField) to be definitions of x. These changes are in line with the user expectations we've observed.
There is now a DataFlow::localExprFlow predicate and a TaintTracking::localExprTaint predicate to make it easy to use the most common case of local data flow and taint: from one Expr to another.
The member predicates of the FunctionInput and FunctionOutput classes have been renamed for clarity (e.g. isOutReturnPointer() to isReturnValueDeref()). The existing member predicates have been deprecated, and will be removed in a future release. Code that uses the old member predicates should be updated to use the corresponding new member predicate.