Add variable length tests for emit_ref in trace-condition.exp

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.