Merge pull request #38160 from augusto2112/mangle-empty-type-list

Mangle empty type lists on anonymous contexts.

Author: augusto2112

test/Demangle/Inputs/manglings.txt

@@ -412,3 +412,4 @@ $s4test10returnsOptyxycSgxyScMYccSglF ---> test.returnsOpt<A>((@Swift.MainActor
 $sSvSgA3ASbIetCyyd_SgSbIetCyyyd_SgD ---> (@escaping @convention(thin) @convention(c) (@unowned Swift.UnsafeMutableRawPointer?, @unowned Swift.UnsafeMutableRawPointer?, @unowned (@escaping @convention(thin) @convention(c) (@unowned Swift.UnsafeMutableRawPointer?, @unowned Swift.UnsafeMutableRawPointer?) -> (@unowned Swift.Bool))?) -> (@unowned Swift.Bool))?
 $s4test10returnsOptyxycSgxyScMYccSglF ---> test.returnsOpt<A>((@Swift.MainActor () -> A)?) -> (() -> A)?
 $s1t10globalFuncyyAA7MyActorCYiF ---> t.globalFunc(isolated t.MyActor) -> ()
+$s13__lldb_expr_110$10016c2d8yXZ1B10$10016c2e0LLC ---> __lldb_expr_1.(unknown context at $10016c2d8).(B in $10016c2e0)