RFR: Avoid using uintx in ShenandoahHeapRegion

[Aleksey Shipilev]

This is a proper solution for platforms where size_t != uintx.

Testing: tier1_gc_shenandoah

diff -r 8cb652cfde2c src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.cpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.cpp  Thu Aug 23 10:42:40 2018 +0200
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.cpp  Thu Aug 23 11:10:25 2018 +0200
@@ -570,5 +570,5 @@
   }

-  uintx region_size;
+  size_t region_size;
   if (FLAG_IS_DEFAULT(ShenandoahHeapRegionSize)) {
     if (ShenandoahMinRegionSize > initial_heap_size / MIN_NUM_REGIONS) {
@@ -638,5 +638,5 @@
   // 2. This means that region_size is the largest power of 2 that's
   // <= what we've calculated so far.
-  region_size = ((uintx)1 << region_size_log);
+  region_size = (1u << region_size_log);

   // Now, set up the globals.
@@ -648,5 +648,5 @@

   guarantee(RegionSizeBytes == 0, "we should only set it once");
-  RegionSizeBytes = (size_t)region_size;
+  RegionSizeBytes = region_size;
   RegionSizeWords = RegionSizeBytes >> LogHeapWordSize;
   assert (RegionSizeWords*HeapWordSize == RegionSizeBytes, "sanity");


Thanks,
-Aleksey