Added em_use

git-svn-id: svn://svn.cc65.org/cc65/trunk@1719 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/em/em_use.s

@@ -0,0 +1,17 @@
+;
+; Ullrich von Bassewitz, 2002-11-29
+;
+; void* __fastcall__ em_use (unsigned page);
+; /* Tell the driver that the memory window is associated with a given page.
+;  * This call is very similar to em_map. The difference is that the driver
+;  * does not necessarily transfer the current contents of the extended
+;  * memory into the returned window. If you're going to just write to the
+;  * window and the current contents of the window are invalid or no longer
+;  * use, this call may perform better than em_map.
+;  */
+
+
+        .include        "em-kernel.inc"
+
+       	_em_use         = emd_use               ; Use driver entry
+