escapeshellargs() uses different quotation mark characters between Linux
and Windows, so tests were failing on Windows. This change uses a
regular expression instead.
Rename `Type\IntegerValue` to `Type\Integer`. It was originally named
`IntegerValue` because static analysis sees `Integer` in docblock
annotations and treats it as the native `int` type. `Integer` is not a
reserved word in PHP, so it should be named `Integer` for consistency
with other types in this library. When using it, a class alias prevents
static analysis from complaining.
As documented in https://wiki.php.net/rfc/use_global_elements, the engine (by default) does a local namespace
lookup, then falls back to global namespace when first calling a global function referenced in namespaced code,
unless that function is referenced via fully qualified name (FQN).
By using the FQN, the actual symbol can be looked up at compile-time, both by the PHP engine and by static analysis
tooling, allowing for compiler (in particular) optimizations to replace known hot-path functions with specialized opcodes.
Sadly, no actual benchmark at hand: the improvements can be minimal or massive, depending on where this library is
used (tight loops being most relevant).