gccrs: Compile pattern match statements into conditional statements

gccrs: Compile pattern match statements into conditional statements

gcc/rust/ChangeLog:

	* backend/rust-compile-expr.cc
	(patterns_mergeable): Remove.
	(struct PatternMerge): Remove.
	(sort_tuple_patterns): Remove.
	(simplify_tuple_match): Remove.
	(CompileExpr::visit): Modify compilation of MatchExpr.

	* backend/rust-compile-pattern.cc
	(CompilePatternCaseLabelExpr::visit): Replace with...
	(CompilePatternCheckExpr::visit): ...this.
	* backend/rust-compile-pattern.h
	(class CompilePatternCaseLabelExpr): Replace with...
	(class CompilePatternCheckExpr): ...this.

	* backend/rust-compile-type.cc
	(TyTyResolveCompile::get_implicit_enumeral_node_type):
	Make enumeral type equivalent to isize.

Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>