Use intptr_t to cast a pointer.

Avoids warnings especially when compiling for 64-bit Windows.

Patch by Stephen Sheldon [sfsheldo gmail].

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@37279 b3059339-0415-0410-9bf9-f77b7e298cf2
Add stdint.h include for intptr_t.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@37280 b3059339-0415-0410-9bf9-f77b7e298cf2