Fixes a number of issue related to test portability on Windows.

99% of this CL is simply moving calls to "import pexpect" to a more
narrow scope - i.e. the function that actually runs a particular
test.  This way the test suite can run on Windows, which doesn't have
pexpect, and the individual tests that use pexpect can be disabled on
a platform-specific basis.

Additionally, this CL fixes a few other cases of non-portability.
Notably, using "ps" to get the command line, and os.uname() to
determine the architecture don't work on Windows.  Finally, this
also adds a stubbed out builder_win32 module.

The full test suite runs correctly on Windows after this CL, although
there is still some work remaining on the C++ side to fix one-shot
script commands from LLDB (e.g. script print "foo"), which currently
deadlock.

Reviewed by: Todd Fiala

Differential Revision: http://reviews.llvm.org/D4573

llvm-svn: 213343
diff --git a/lldb/test/tools/lldb-gdbserver/gdbremote_testcase.py b/lldb/test/tools/lldb-gdbserver/gdbremote_testcase.py
index b0e9512..a079358 100644
--- a/lldb/test/tools/lldb-gdbserver/gdbremote_testcase.py
+++ b/lldb/test/tools/lldb-gdbserver/gdbremote_testcase.py
@@ -5,7 +5,6 @@
 import errno
 import os
 import os.path
-import pexpect
 import platform
 import random
 import re
@@ -180,6 +179,7 @@
 
     def launch_debug_monitor(self, attach_pid=None):
         # Create the command line.
+        import pexpect
         commandline = "{}{} localhost:{}".format(self.debug_monitor_exe, self.debug_monitor_extra_args, self.port)
         if attach_pid:
             commandline += " --attach=%d" % attach_pid