Accept namespaces in sitePassByRefFunctions (#351)

* Add test for using a namespace in sitePassByRefFunctions

* Add namespace to function names when looking for pass-by-reference

* Make sure cache is not used before it is ready

* Make sure we don't try to use null in getPassByReferenceFunction

* Init passByRefFunctionsCache to null explicitly

Allow finding arrow function variables when arrow function is in file…

… scope (#347)

* Add test for arrow function in global scope

* Still look for arrow func when var scope is 0

`findVariableScopeExceptArrowFunctions()` can return null if it finds no
scope, but it can also return 0 which is the file level scope. The
additional code to look for arrow function scope needs to operate even
on 0.

* Remove duplicate call to findVariableScopeExceptArrowFunctions

* Remove phpcs-import-detection depdendency since it is unused

* Remove ImportDetection on phpcs config

Only search for nested arrow functions if necessary (#342)

* Do not search for nested arrow func outside of arrow func

* Recursively search for containing arrow function

* Guard for no enclosing scope

Handle compact inside arrow functions (#339)

* Add test for compact used within arrow function

* Process every variable in compact separately

* Also track position of compact variables

* Guard against missing compact variable position

* Fix linting errors

* Also add test for outside var

fix: Process variable before the end of scope (#324)

* test: add test for variable use in short open echo

When a variable is used in a short php open echo tag, it should be
marked as used.

* fix: process variable before the end of scope

fixes #323

When the last php code is a short php open echo tag using a variable,
process the variable before processing the end of scope.

Fix nullable constructor promotion detection (#321)

Fix nullable constructor promotion detection (#321)

Make sure that recursive search of list assignments stays inside them (…

…#318)

* Add tests for destructuring assignment with array arg

* Make sure that recursive search of list assignments stays inside them

Do not close scope of ref reassignment when inside else (#306)

* Add test for unused variable

* Add more debug lines to reference processing

* Do not close scope of ref reassignment when inside else

* Verify all regexps are non-empty strings

This will please psalm, I hope.

* Add guard for empty preg_match_all in processVariableInString

Allow newlines in arrow functions (#301)

* Add test for arrow func with newlines

* Allow newlines in arrow functions

* Add test for new class in arrow function

* Add some more arrow function tests