[newlib-cygwin] _dll_crt0: Drop incorrect check for being started from parent main thread

[Corinna Vinschen <corinna at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=35d344babe154bde4e5dfcc01638251cc50e2e79

commit 35d344babe154bde4e5dfcc01638251cc50e2e79
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Fri Mar 10 20:28:09 2017 +0100

    _dll_crt0: Drop incorrect check for being started from parent main thread
    
    This test was broken from the start.  It leads to creating a completely
    new stack for the main thread of the child process when started from
    the main thread of the parent.  However, the main thread of a process
    can easily running on a completely different stack, if the parent's main
    thread was created by calling fork() from a pthread.  For an example,
    see https://cygwin.com/ml/cygwin/2017-03/msg00113.html
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/dcrt0.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/cygwin/dcrt0.cc b/winsup/cygwin/dcrt0.cc
index 8ddee0c..ea6adcb 100644
--- a/winsup/cygwin/dcrt0.cc
+++ b/winsup/cygwin/dcrt0.cc
@@ -1041,7 +1041,7 @@ _dll_crt0 ()
      under our own control and avoids collision with the OS. */
   if (!dynamically_loaded)
     {
-      if (!in_forkee || fork_info->from_main)
+      if (!in_forkee)
 	{
 	  /* Must be static since it's referenced after the stack and frame
 	     pointer registers have been changed. */