pop - pop esp is special

 - Intel(R) Architecture Software Developer's Manual, Volume 2: Instruction Set Reference Manual
   Page 571ff: The POP ESP instruction increments the stack pointer (ESP)
   before data at the old top of stack is written into the destination.
   Incorrect behaviour was incrementing esp after data was written into it.

Thanks to Paul Banks for notice and patch.

Signed-off-by: Paul Banks <foss@paulbanks.org>

include/emu/emu_cpu_stack.h

@@ -93,7 +93,8 @@
 if( ret != 0 ) \
 	return ret; \
 else \
-	cpu->reg[esp] += 4; }
+  if ( dst_p != &cpu->reg[esp] ) \
+  	cpu->reg[esp] += 4; }
 
 #define POP_WORD(cpu, dst_p) \
 { int32_t ret = emu_memory_read_word(cpu->mem, cpu->reg[esp], dst_p); \