[Darwin, PPC, testsuite] Fix pr71785 testcase for Darwin.

[Darwin, PPC, testsuite] Fix pr71785 testcase for Darwin.

Firstly, we adjust the test conditions to use non-PIC code for Darwin.
Secondly, we have to account for out-of-line GPR restores which gives
a false positive on one of the scan-assembler-not.  Lastly, we make the
test a bit more specific for Darwin - that it looks for absence of
branches to local labels.

2019-06-23  Iain Sandoe  <iain@sandoe.co.uk>

	* gcc.target/powerpc/pr71785.c: For Darwin, make test non-PIC,
	expect the out-of-line GPR restore, and test specifically for
	absence of branches to local labels.

From-SVN: r272601