Use separate random number generator for each randomization pass

src/IceRegAlloc.cpp

Index: src/IceRegAlloc.cpp
diff --git a/src/IceRegAlloc.cpp b/src/IceRegAlloc.cpp
index 0d9afba44d55c72f68d4bab6ac184380781bf21b..efbe6446467f934e23c4f1f37f1f5a79dec88600 100644
--- a/src/IceRegAlloc.cpp
+++ b/src/IceRegAlloc.cpp
@@ -250,11 +250,11 @@ void LinearScan::init(RegAllocKind Kind) {
   }
 
   auto CompareRanges = [](const Variable *L, const Variable *R) {
-      InstNumberT Lstart = L->getLiveRange().getStart();
-      InstNumberT Rstart = R->getLiveRange().getStart();
-      if (Lstart == Rstart)
-        return L->getIndex() < R->getIndex();
-      return Lstart < Rstart;
+    InstNumberT Lstart = L->getLiveRange().getStart();
+    InstNumberT Rstart = R->getLiveRange().getStart();
+    if (Lstart == Rstart)
+      return L->getIndex() < R->getIndex();
+    return Lstart < Rstart;
   };
   // Do a reverse sort so that erasing elements (from the end) is fast.
   std::sort(Unhandled.rbegin(), Unhandled.rend(), CompareRanges);