re PR tree-optimization/17549 (10% increase in codesize with C code compared to GCC 3.3)

	PR tree-optimization/17549
	* tree-outof-ssa.c (find_replaceable_in_bb): Do not allow
	TER to replace a DEF with its expression if the DEF and the
	rhs of the expression we replace into have the same root
	variable.

From-SVN: r94853