test: add fixtures to reproduce the failure

Signed-off-by: Alexander Bezzubov <[email protected]>

Author: bzz

fixtures/string-literal.js

@@ -1,3 +1,9 @@
 a = "a"
 u8 = "ё"
 bc = "b\nc"
+
+var escSlash = '\0SLASH'+Math.random()+'\0';
+var escOpen = '\0OPEN'+Math.random()+'\0';
+var escClose = '\0CLOSE'+Math.random()+'\0';
+var escComma = '\0COMMA'+Math.random()+'\0';
+var escPeriod = '\0PERIOD'+Math.random()+'\0';