re PR tree-optimization/38275 (bootstrap failure when -ftree-parallelize-loops=4...

re PR tree-optimization/38275 (bootstrap failure when -ftree-parallelize-loops=4 is enabled)

PR tree-optimization/38275
	* tree-parloops.c (parallelize_loops): Replace profitability condition
        for expected number of iterations.
        * testsuite/gcc.dg/autopar/reduc-1char.c: Increase number
        of iterations. Adjust the logic accordingly.
        * testsuite/gcc.dg/autopar/reduc-2char.c: Ditto.
        * testsuite/gcc.dg/autopar/reduc-1.c: Ditto.
        * testsuite/gcc.dg/autopar/reduc-2.c: Ditto.
        * testsuite/gcc.dg/autopar/reduc-3.c: Ditto.
        * testsuite/gcc.dg/autopar/reduc-6.c: Ditto.
        * testsuite/gcc.dg/autopar/reduc-7.c: Ditto.
        * testsuite/gcc.dg/autopar/reduc-8.c: Ditto.
        * testsuite/gcc.dg/autopar/reduc-9.c: Ditto.
        * testsuite/gcc.dg/autopar/pr39500-1.c: Ditto.
        * testsuite/gcc.dg/autopar/reduc-1short.c: Ditto.
        * testsuite/gcc.dg/autopar/reduc-2short.c: Ditto.
        * testsuite/gcc.dg/autopar/parallelization-1.c: Ditto.

From-SVN: r151372