Order jump tables for deterministic or randomized emission.

BUG=
R=stichnot@chromium.org, jvoung, stichnot

Review URL: https://codereview.chromium.org/1260183008.

src/IceSwitchLowering.h

diff --git a/src/IceSwitchLowering.h b/src/IceSwitchLowering.h
index 34c9373..57c7d3c 100644
--- a/src/IceSwitchLowering.h
+++ b/src/IceSwitchLowering.h
@@ -79,7 +79,6 @@
 /// ELF section once the offsets from the start of the function are known.
 class JumpTableData {
   JumpTableData() = delete;
-  JumpTableData(const JumpTableData &) = delete;
   JumpTableData &operator=(const JumpTableData &) = delete;
 
 public:
@@ -87,7 +86,9 @@
       : FuncName(FuncName), Id(Id) {
     TargetOffsets.reserve(NumTargets);
   }
+  JumpTableData(const JumpTableData &) = default;
   JumpTableData(JumpTableData &&) = default;
+  JumpTableData &operator=(JumpTableData &&) = default;
 
   void pushTarget(intptr_t Offset) { TargetOffsets.emplace_back(Offset); }
 
@@ -98,8 +99,8 @@
   }
 
 private:
-  const IceString FuncName;
-  const SizeT Id;
+  IceString FuncName;
+  SizeT Id;
   std::vector<intptr_t> TargetOffsets;
 };