New Utils\ControlStructures class

[jrfnl]

This adds three new utility methods:

• hasBody() - to check whether a control structure has a body and optionally whether that body is non-empty. Returns boolean.
  This is a helper function to distinguish between structures like while (++$i < 10); and while (++$i < 10) { /* do something */ }.
• isElseIf() - to check whether an T_IF or T_ELSE token is part of an else if. Returns boolean.
• getDeclareScopeOpenClose() - to retrieve the scope open/close pointers for declare statements. Returns an array with the stack pointers or false if a file based statement or if the scope open/close pointers could not be determined.
  Declare statements come in three flavours:
  • file based, without body: declare(ticks=1);;
  • scoped using curly braces;
  • scoped using the alternative control structure syntax.
    In that last case, PHPCS does not assign the scope open/close indexes in the $tokens array. A PR is open to fix this, but for any sniff which needs to support versions of PHPCS prior to the version in which that PR will be merged, this helper method can retrieve the scope open/close indexes.

This commit also adds two convenience token arrays for working with control structures to the PHPCSUtils\Tokens\Collections class.

• $alternativeControlStructureSyntaxTokens - tokens which can use the alternative syntax for control structures.
• $controlStructureTokens - control structure tokens.

Includes extensive dedicated unit tests.