Fix independent-cloneids-1.c testcase (PR88318)

Fix independent-cloneids-1.c testcase (PR88318)

The testcase uses REs like {(?n)\m_*bar[.$_]constprop[.$_]0:} to find
what functions are defined.  But, this also matches lines like
.L.bar.constprop.0:(which are used on powerpc64-linux).
The "(?n)" doesn't do anything here either.  We should use "^" here
instead of just "\m".

	PR testsuite/88318
	* gcc.dg/independent-cloneids-1.c: Use ^ not \m.

From-SVN: r267063