vpx[dec|enc]: Clean up target OS based IO focused preproc abuse.

Relocate it to tools_common.h so we can stop duping this code
everywhere.

BUG=https://code.google.com/p/webm/issues/detail?id=660

Change-Id: If8aa49b74d297273cd9fd7006b2767837055a359

tools_common.h

@@ -12,6 +12,46 @@
 
 #include <stdio.h>
 
+#include "./vpx_config.h"
+
+#if defined(_MSC_VER)
+/* MSVS doesn't define off_t, and uses _f{seek,tell}i64. */
+typedef __int64 off_t;
+#define fseeko _fseeki64
+#define ftello _ftelli64
+#elif defined(_WIN32)
+/* MinGW defines off_t as long and uses f{seek,tell}o64/off64_t for large
+ * files. */
+#define fseeko fseeko64
+#define ftello ftello64
+#define off_t off64_t
+#endif  /* _WIN32 */
+
+#if CONFIG_OS_SUPPORT
+#if defined(_MSC_VER)
+#include <io.h>  /* NOLINT */
+#define snprintf _snprintf
+#define isatty   _isatty
+#define fileno   _fileno
+#else
+#include <unistd.h>  /* NOLINT */
+#endif  /* _MSC_VER */
+#endif  /* CONFIG_OS_SUPPORT */
+
+/* Use 32-bit file operations in WebM file format when building ARM
+ * executables (.axf) with RVCT. */
+#if !CONFIG_OS_SUPPORT
+typedef long off_t;  /* NOLINT */
+#define fseeko fseek
+#define ftello ftell
+#endif  /* CONFIG_OS_SUPPORT */
+
+#define LITERALU64(hi, lo) ((((uint64_t)hi) << 32) | lo)
+
+#ifndef PATH_MAX
+#define PATH_MAX 512
+#endif
+
 #define VP8_FOURCC (0x30385056)
 #define VP9_FOURCC (0x30395056)
 #define VP8_FOURCC_MASK (0x00385056)