cmd/go: add distribution-specific info for Linux to bug command
Also remove the hard-coded path for getting glibc information.
As an example, the following is the diff for `go bug` on Ubuntu before
and after the change:
>>>
--- /tmp/01 2016-09-13 15:08:53.
202758043 +0530
+++ /tmp/02 2016-09-13 21:38:17.
485039867 +0530
@@ -1,7 +1,7 @@
Please check whether the issue also reproduces on the latest release, go1.7.1.
```
-go version devel +
bdb3b79 Wed Sep 7 03:23:44 2016 +0000 linux/amd64
+go version devel +
cb13150 Wed Sep 7 09:46:58 2016 +0530 linux/amd64
GOARCH="amd64"
GOBIN=""
GOEXE=""
@@ -18,5 +18,23 @@
CXX="g++"
CGO_ENABLED="1"
uname -sr: Linux 4.4.0-36-generic
+Distributor ID: Ubuntu
+Description: Ubuntu 16.04.1 LTS
+Release: 16.04
+Codename: xenial
+/lib/x86_64-linux-gnu/libc.so.6: GNU C Library (Ubuntu GLIBC 2.23-0ubuntu3) stable release version 2.23, by Roland McGrath et al.
gdb --version: GNU gdb (Ubuntu 7.11.1-0ubuntu1~16.04) 7.11.1
```
<<<
Change-Id: I7e3730a797af0f94d6e43fe4743ab48bc0f11f1b
Reviewed-on: https://go-review.googlesource.com/28581
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>