RFR [8]: Fix MacOS/Clang build failure

[Aleksey Shipilev]

Following up on MacOS/Clang build failures. This only affects sh/jdk8, because we have different
type for _tax_rate there:

diff -r 73e73472762b src/share/vm/gc_implementation/shenandoah/shenandoahPacer.cpp
--- a/src/share/vm/gc_implementation/shenandoah/shenandoahPacer.cpp	Thu May 31 12:29:14 2018 +0200
+++ b/src/share/vm/gc_implementation/shenandoah/shenandoahPacer.cpp	Mon Jun 04 12:51:54 2018 +0200
@@ -147,7 +147,7 @@
 bool ShenandoahPacer::claim_for_alloc(size_t words, bool force) {
   assert(ShenandoahPacing, "Only be here when pacing is enabled");

-  intptr_t tax = MAX2<intptr_t>(1, words * OrderAccess::load_acquire(&_tax_rate));
+  intptr_t tax = MAX2<intptr_t>(1, (intptr_t)(words * OrderAccess::load_acquire(&_tax_rate)));

   intptr_t cur = 0;
   intptr_t new_val = 0;


Testing: hotspot_gc_shenandoah, sh/jdk8 mac build

Thanks,
-Aleksey