adb: fix shell_service_protocol_test for Windows.

Adds missing #ifdef guards to shell_service_protocol_test.cpp so the
test compiles on Windows.

Also fixes a bug in Windows socketpair write implementation. Previously
it was only checking for a closed pipe if the write happened to block.
This adds an additional pre-check to exit immediately on a closed pipe.

These two changes allow the test to compile and pass on Windows.

Change-Id: Ib8853ed72f015fc0d623da47c32982cb3ffa4a3d
diff --git a/adb/sysdeps_win32.cpp b/adb/sysdeps_win32.cpp
index c5aad02..5b23c79 100644
--- a/adb/sysdeps_win32.cpp
+++ b/adb/sysdeps_win32.cpp
@@ -1121,6 +1121,11 @@
     BIPD(( "bip_buffer_write: enter %d->%d len %d", bip->fdin, bip->fdout, len ));
     BIPDUMP( src, len );
 
+    if (bip->closed) {
+        errno = EPIPE;
+        return -1;
+    }
+
     EnterCriticalSection( &bip->lock );
 
     while (!bip->can_write) {