* dcrt0.cc (dll_crt0_0): Call malloc_init and user_shared_initialize_1

here in case we're dynamically loaded.  Explain why.
	(dll_crt0_1): Call user_shared_initialize_1 from here.
	* mount.cc (is_native_path): New inline function testing for native
	and long Win32 path prefix.
	(is_unc_share): Remove long WIn32 path prefix test.
	(mount_info::create_root_entry): Use PATH_MAX buffer.
	(mount_info::init): Ditto.
	(mount_info::add_item): Test for is_native_path as well.
	* path.cc (normalize_win32_path): Simplify native path prefix code.
	* shared.cc (user_shared_initialize_1): New function taking user
	shared initialization code relying on malloc and cygtls.
	(user_shared_initialize): Move mountinfo initialization to
	user_shared_initialize_1.
	* shared_info.h (user_shared_initialize_1): Declare.
	* syscalls.cc (seteuid32): Call user_shared_initialize_1 after user
	changed.

winsup/cygwin/dcrt0.cc

@@ -752,6 +752,20 @@ dll_crt0_0 ()
   events_init ();
   tty_list::init_session ();
 
+  if (dynamically_loaded)
+    {
+      /* When dynamically loaded. we must initialize the user shared memory
+	 entirely here since dll_crt0_1 will not be called.  Stuff in
+	 user_shared_initialize_1 relies on malloc and cygtls being available
+	 and the initialization isn't finished without calling it.  In the
+	 non-dynamical case this is called in dll_crt0_1, because malloc_init
+	 has to test for overloaded malloc functionality in the application.
+	 That's not an issue when cygwin is loaded dynamically.  It will just
+	 use its own malloc area. */
+      malloc_init ();
+      user_shared_initialize_1 ();
+    }
+
   debug_printf ("finished dll_crt0_0 initialization");
 }
 
@@ -774,6 +788,8 @@ dll_crt0_1 (void *)
   ProtectHandle (hMainProc);
   ProtectHandle (hMainThread);
 
+  user_shared_initialize_1 ();
+
   cygheap->cwd.init ();
 
   /* Initialize pthread mainthread when not forked and it is safe to call new,