adb: "support" O_CLOEXEC in adb_open on Windows.

Previously, we were rejecting the flag and failing with EINVAL. File
handles aren't inherited by default, so just ignore the flag.

Bug: http://b/123753498
Test: adb install --streaming foo.apk
Change-Id: I17401fcdd58024956d47a5c4c0c57b06831d9817

adb/sysdeps_win32.cpp

@@ -356,6 +356,9 @@ int adb_open(const char* path, int options) {
     DWORD desiredAccess = 0;
     DWORD shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
 
+    // CreateFileW is inherently O_CLOEXEC by default.
+    options &= ~O_CLOEXEC;
+
     switch (options) {
         case O_RDONLY:
             desiredAccess = GENERIC_READ;