mGCA: Support directly represented negated literals

[khyperia]

fixes #152123

PatExprKind already awkwardly tacks on a negated: bool for the same purpose:

rust/compiler/rustc_hir/src/hir.rs

Lines 1954 to 1959 in 8bccf12

	Lit {
	lit: Lit,
	// FIXME: move this into `Lit` and handle negated literal expressions
	// once instead of matching on unop neg expressions everywhere.
	negated: bool,
	},

perhaps one day we should indeed do that FIXME...

r? @BoxyUwU

[rustbot]

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

HIR ty lowering was modified

cc @fmease

[BoxyUwU]

can you add tests for "nonsensical" negated literals, e.g. -true { -true } -":3" { ":3" }, ah and I guess also -1_usize and { -1_usize }.