x/tools/cmd/heapview: rename heapdump to heapview

Updates golang/go#16410

Change-Id: I0133971f9a1149da6d88180fc2e378003f189cc8
Reviewed-on: https://go-review.googlesource.com/25101
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/cmd/heapdump/main.go b/cmd/heapview/main.go
similarity index 74%
rename from cmd/heapdump/main.go
rename to cmd/heapview/main.go
index c5ede8f..7c0170c 100644
--- a/cmd/heapdump/main.go
+++ b/cmd/heapview/main.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// heapdump is a tool for inspecting and analyzing Go heap dumps.
+// heapview is a tool for viewing Go heap dumps.
 package main
 
 func main() {