gccrs: resolve: Name resolve trait bounds properly

gccrs: resolve: Name resolve trait bounds properly

gcc/rust/ChangeLog:

	* resolve/rust-ast-resolve-type.cc (ResolveTypeToCanonicalPath::visit): Resolve additional
	trait bounds.
	* resolve/rust-late-name-resolver-2.0.cc (Late::visit): Error out properly on unresolved
	type-path instead of crashing.

gcc/testsuite/ChangeLog:

	* rust/compile/nr2/exclude: Exclude additional-trait-bounds2 for different error message.
	* rust/compile/additional-trait-bounds1.rs: New test.
	* rust/compile/additional-trait-bounds2.rs: New test.
	* rust/compile/additional-trait-bounds2nr2.rs: New test.