cmd/compile/internal/typecheck: simplify tcAppend

After CL 418514, Unified IR now always write concrete type of constant
expressions, thus we don't need to handle untyped string anymore.

Change-Id: Ic930ee2418746ca9f4a5122c614e077bef8d7eb4
Reviewed-on: https://go-review.googlesource.com/c/go/+/422041
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

diff --git a/src/cmd/compile/internal/typecheck/func.go b/src/cmd/compile/internal/typecheck/func.go
index 7790e65ca22affd126452160a18df5c7fde3e05f..40eab64a5434e113710bd343db99a87f5c8bee3c 100644 (file)
--- a/src/cmd/compile/internal/typecheck/func.go
+++ b/src/cmd/compile/internal/typecheck/func.go
@@ -460,11 +460,6 @@ func tcAppend(n *ir.CallExpr) ir.Node {
                        return n
                }
 
-               if t.Elem().IsKind(types.TUINT8) && args[1].Type().IsString() {
-                       args[1] = DefaultLit(args[1], types.Types[types.TSTRING])
-                       return n
-               }
-
                // AssignConv is of args[1] not required here, as the
                // types of args[0] and args[1] don't need to match
                // (They will both have an underlying type which are