Move trace conditions tests from ftrace.exp to trace-condition.exp

Move trace conditions tests from ftrace.exp to trace-condition.exp

This patch moves conditional tests that were done in ftrace.exp to
trace-condition.exp.

Note that emit_ref is now tested by the anarg local variable there is no
need to test the register directly.

All emit calls have been tested using asserts before / after the move, to
ensure that the tests cover the same functions.

Note that these function were not covered before and are still not:
emit_gt_goto, emit_lt_goto, emit_pop, emit_unsigned_less.

gdb/testsuite/ChangeLog:

	* gdb.trace/ftrace.exp (test_ftrace_condition): Remove.
	Move condition tests...
	* gdb.trace/trace-condition.exp: Here.