Don't try to build CD-ROM support on Emscripten.

extras/buildbot-emscripten.sh

@@ -50,7 +50,6 @@ echo "Setting up Emscripten SDK environment..."
 source "$ENVSCRIPT"
 
 echo "Setting up..."
-set -x
 cd "$PHYSFSBASE"
 rm -rf buildbot
 mkdir buildbot

src/physfs_platforms.h

@@ -61,6 +61,10 @@
 #  define PHYSFS_PLATFORM_BSD 1
 #  define PHYSFS_PLATFORM_UNIX 1
 #  define PHYSFS_PLATFORM_POSIX 1
+#elif defined(__EMSCRIPTEN__)
+#  define PHYSFS_NO_CDROM_SUPPORT 1
+#  define PHYSFS_PLATFORM_UNIX 1
+#  define PHYSFS_PLATFORM_POSIX 1
 #elif defined(unix) || defined(__unix__)
 #  define PHYSFS_PLATFORM_UNIX 1
 #  define PHYSFS_PLATFORM_POSIX 1