Do not discard stacktraces on gen_server exits

Prior to this patch, the stacktrace of an error or
exit in a callback would always be discarded in crash
reports. For example, an exit(crashed) in handle_call/3
would emit:

    =CRASH REPORT==== 10-May-2017::14:15:50 ===
      crasher:
        initial call: gen_server_SUITE:init/1
        pid: <0.201.0>
        registered_name: []
        exception exit: crashed
          in function  gen_server:terminate/8 (src/gen_server.erl, line 828)

Note that the stacktrace is pointing to the gen_server
internal terminate implementation that calls exit/1.

This patch uses erlang:raise/3 so the stacktrace is not
lost, allowing proc_lib to show the class, reason
and stacktrace coming from the user implementation
(in this case gen_server_SUITE):

    =CRASH REPORT==== 10-May-2017::14:16:44 ===
      crasher:
        initial call: gen_server_SUITE:init/1
        pid: <0.197.0>
        registered_name: []
        exception exit: crashed
          in function  gen_server_SUITE:handle_call/3 (gen_server_SUITE.erl, line 1529)

This change is completely backwards compatible as
using erlang:raise/3 will still emit the same exit
reason to any linked process and monitor as before.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/stdlib/test/gen_server_SUITE.erl b/lib/stdlib/test/gen_server_SUITE.erl
index 7e3c71715e..2e9dc4d4fb 100644
--- a/lib/stdlib/test/gen_server_SUITE.erl
+++ b/lib/stdlib/test/gen_server_SUITE.erl
@@ -404,7 +404,7 @@ crash(Config) when is_list(Config) ->
     end,
     receive
 	{error_report,_,{Pid4,crash_report,[List4|_]}} ->
-	    {exit,crashed,_} = proplists:get_value(error_info, List4),
+	    {exit,crashed,[{?MODULE, handle_call, 3, _}|_]} = proplists:get_value(error_info, List4),
 	    Pid4 = proplists:get_value(pid, List4);
 	Other4 ->
 	    io:format("Unexpected: ~p", [Other4]),