Revert "Revert "Add a way to turn off unique_fd's operator int.""

The original commit broke aosp-master-with-phones, because of
vendor libraries the depended on the int versions of libbase functions.

This patch reverts the revert, and also adds ABI-compatibility shims for
the replaced functions.

This reverts commit 2c58e1924a7bf1b44049764fddb40c1704dc288f.

Bug: http://b/131312539
Test: treehugger
Test: forrest run of aosp-master-with-phones
Change-Id: I75cc84ec8d963e20862f7662e8e2f409471f41cc
diff --git a/adb/adb_utils.h b/adb/adb_utils.h
index 8b0dcee..faad03d 100644
--- a/adb/adb_utils.h
+++ b/adb/adb_utils.h
@@ -26,6 +26,7 @@
 #include <android-base/macros.h>
 
 #include "adb.h"
+#include "adb_unique_fd.h"
 
 void close_stdin();
 
@@ -51,7 +52,7 @@
 [[noreturn]] void error_exit(const char* fmt, ...) __attribute__((__format__(__printf__, 1, 2)));
 [[noreturn]] void perror_exit(const char* fmt, ...) __attribute__((__format__(__printf__, 1, 2)));
 
-bool set_file_block_mode(int fd, bool block);
+bool set_file_block_mode(borrowed_fd fd, bool block);
 
 // Given forward/reverse targets, returns true if they look sane. If an error is found, fills
 // |error| and returns false.