gc: preserve uint8 and byte distinction in errors, import data

There is no semantic change here, just better errors.
If a function says it takes a byte, and you pass it an int,
the compiler error now says that you need a byte, not
that you need a uint8.

Groundwork for rune.

R=ken2
CC=golang-dev
https://golang.org/cl/5300042

1 files changed, 19 insertions, 0 deletions

diff --git a/test/alias.go b/test/alias.go
new file mode 100644
index 0000000000..6039b3183f
--- /dev/null
+++ b/test/alias.go
@@ -0,0 +1,19 @@
+// errchk $G -e $D/$F.go
+
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+// Test that error messages say what the source file says
+// (uint8 vs byte).
+
+func f(byte) {}
+func g(uint8) {}
+
+func main() {
+	var x int
+	f(x)  // ERROR "byte"
+	g(x)  // ERROR "uint8"
+}