Eliminate some ambiguity for IsString [a]
The libraries list resolved to make a modification to the
String instance for
IsString to resolve certain ambiguous cases. One example is:
"hello" ++ " world"
This case can be resolved by making the instance:
instance (a ~ Char) => IsString [a] where ...
instance IsString [Char] where ...
as the former matches only based on the head being
[a], and subsequently determines
a ~ Char, rather than only matching when other factors cause the head to be fully resolved to