cmd/viewcore: don't try to build for GOARCH=wasm

It doesn't build for GOOS=js GOARCH=wasm the same reason it doesn't
build for aix and plan9: the readline dependency doesn't support it.

For golang/go#61104.

Change-Id: Ic7f45fda06c2b01555048e2e167ae0e188b2b492
Cq-Include-Trybots: luci.golang.try:x_debug-gotip-js-wasm
Reviewed-on: https://go-review.googlesource.com/c/debug/+/533696
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/cmd/viewcore/html.go b/cmd/viewcore/html.go
index 15b3dc3..0ec01b0 100644
--- a/cmd/viewcore/html.go
+++ b/cmd/viewcore/html.go
@@ -2,10 +2,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !aix && !plan9
-// +build !aix,!plan9
+//go:build !aix && !plan9 && !wasm
+// +build !aix,!plan9,!wasm
 
-// (https://golang.org/issue/32839)
+// (go.dev/issue/32839)
 
 package main
 
diff --git a/cmd/viewcore/main.go b/cmd/viewcore/main.go
index c5842ee..076fdf3 100644
--- a/cmd/viewcore/main.go
+++ b/cmd/viewcore/main.go
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Skip aix and plan9 for now: github.com/chzyer/readline doesn't support them.
-// (https://golang.org/issue/32839)
+// Skip some ports that github.com/chzyer/readline doesn't support.
+// (See go.dev/issue/32839.)
 //
-//go:build !aix && !plan9
-// +build !aix,!plan9
+//go:build !aix && !plan9 && !wasm
+// +build !aix,!plan9,!wasm
 
 // The viewcore tool is a command-line tool for exploring the state of a Go process
 // that has dumped core.