Add Str.try_from_str

Author: rtfeldman

src/build/roc/Builtin.roc

@@ -4,6 +4,9 @@ Builtin :: [].{
 
 		contains : Str, Str -> Bool
 		contains = |_str, _other| True
+
+		try_from_str : Str -> Try(Str, [InvalidStr(Str)])
+		try_from_str = |self| Try.Ok(self)
 	}
 
 	List(_item) :: [ProvidedByCompiler].{

src/check/Check.zig

@@ -4763,17 +4763,6 @@ fn checkDeferredStaticDispatchConstraints(self: *Self, env: *Env) std.mem.Alloca
             // Iterate over the constraints
             const constraints = self.types.sliceStaticDispatchConstraints(deferred_constraint.constraints);
             for (constraints) |constraint| {
-                // For try_from_str constraints, skip validation if the type is Str
-                // Str is the default/identity type for string literals and doesn't need try_from_str
-                if (constraint.origin == .try_from_str) {
-                    if (std.mem.eql(u8, type_name_bytes, "Str") or
-                        std.mem.eql(u8, type_name_bytes, "Builtin.Str"))
-                    {
-                        // Str is the default type - no validation needed
-                        continue;
-                    }
-                }
-
                 // Extract the function and return type from the constraint
                 const resolved_constraint = self.types.resolveVar(constraint.fn_var);
                 const mb_resolved_func = resolved_constraint.desc.content.unwrapFunc();