Add regression tests

Author: ahejlsberg

tests/cases/conformance/types/specifyingTypes/typeQueries/circularTypeofWithVarOrFunc.ts

@@ -7,3 +7,20 @@ type typeAlias2 = typeof varOfAliasedType2;
 function func(): typeAlias3 { return null; }
 var varOfAliasedType3 = func();
 type typeAlias3 = typeof varOfAliasedType3;
+
+// Repro from #26104
+
+interface Input {
+  a: number;
+  b: number;
+}
+
+type R = ReturnType<typeof mul>;
+function mul(input: Input): R {
+  return input.a * input.b;
+}
+
+// Repro from #26104
+
+type R2 = ReturnType<typeof f>;
+function f(): R2 { return 0; }