Fix typo in exception message

src/core/Exception.pm

@@ -1123,7 +1123,7 @@ my class X::Syntax::DuplicatedPrefix does X::Syntax {
     method message() {
         my $prefix = $.prefixes.substr(0, 1);
         "Expected a term, but found either infix $.prefixes or redundant prefix $prefix\n"
-        ~ "  (to surppress this message, please use a space like $prefix $prefix)";
+        ~ "  (to suppress this message, please use a space like $prefix $prefix)";
     }
 }