Add variable length tests for emit_ref in trace-condition.exp
    
    This patch add variable length tests for emit_ref by reading the variable
    passed as argument of 8 to 64 bit.
    
    gdb/testsuite/ChangeLog:
    
    	* gdb.trace/trace-condition.c (marker): Adapt signature to 8 to 64
    	bits types.
    	(main): Adapt to 8 to 64 bits types.
    	* gdb.trace/trace-condition.exp: Add new tests.