Make AnnotateChar equality consider annotations

This is needed for consistency with the view of equality we've adopted
for AnnotatedStrings. By making AnnotateChar require annotations to be
equal, we preserve the quality that two strings are equal if all their
characters are equal.

base/strings/annotated.jl

@@ -197,12 +197,20 @@ cmp(a::AbstractString, b::AnnotatedString) = cmp(a, b.string)
 # To avoid method ambiguity
 cmp(a::AnnotatedString, b::AnnotatedString) = cmp(a.string, b.string)
 
+# Annotated strings are equal if their strings and annotations are equal
 ==(a::AnnotatedString, b::AnnotatedString) =
     a.string == b.string && a.annotations == b.annotations
 
 ==(a::AnnotatedString, b::AbstractString) = isempty(a.annotations) && a.string == b
 ==(a::AbstractString, b::AnnotatedString) = isempty(b.annotations) && a == b.string
 
+# Annotated chars are equal if their chars and annotations are equal
+==(a::AnnotatedChar, b::AnnotatedChar) =
+    a.char == b.char && a.annotations == b.annotations
+
+==(a::AnnotatedChar, b::AbstractChar) = isempty(a.annotations) && a.char == b
+==(a::AbstractChar, b::AnnotatedChar) = isempty(b.annotations) && a == b.char
+
 # To prevent substring equality from hitting the generic fallback
 
 function ==(a::SubString{<:AnnotatedString}, b::SubString{<:AnnotatedString})