Remove some additional code that depended on the old type propagation.

pkg/kernel/testcases/type-propagation/stringliteral.baseline.txt

Index: pkg/kernel/testcases/type-propagation/stringliteral.baseline.txt
diff --git a/pkg/kernel/testcases/type-propagation/stringliteral.baseline.txt b/pkg/kernel/testcases/type-propagation/stringliteral.baseline.txt
deleted file mode 100644
index ded8c03629c5fa015f68eeebce5d71f9aec6a687..0000000000000000000000000000000000000000
--- a/pkg/kernel/testcases/type-propagation/stringliteral.baseline.txt
+++ /dev/null
@@ -1,10 +0,0 @@
-library;
-import self as self;
-
-static field dynamic/dart.core::String* {string} color = "brown";
-static field dynamic/dart.core::String* {string} thing = "lazy dog";
-static field dynamic/dart.core::String* {string} phrase = "The quick ${self::color} fox\njumped over the ${self::thing}.\n";
-static field dynamic/dart.core::String* {string} adjacent = "${self::color}${self::color}${self::color}";
-static field dynamic/dart.core::String* {string} linebreaks = "${self::color}\n${self::color}\n${self::color}";
-static field dynamic/dart.core::String* {string} other = "${self::color}\n is \n${self::color}";
-static method main() → dynamic/Null {}