Subzero: Update for LLVM 3.9 (trunk).

The purpose is to allow pnacl-sz to be built within an LLVM checkout (version 3.9 or later), and not require the complex PNaCl build environment.

Within an LLVM checkout, one would do something like the following:
  cd projects
  git clone https://chromium.googlesource.com/native_client/pnacl-subzero
  # change to LLVM build directory
  cmake -G "Ninja" <path_to_llvm_source_dir>
  ninja

A follow-on CL will add in the PNaCl bitcode reader source files that are needed for compiling and linking.

BUG= none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1961743002 .
diff --git a/src/IceCfg.cpp b/src/IceCfg.cpp
index 9a47dd6..f717379 100644
--- a/src/IceCfg.cpp
+++ b/src/IceCfg.cpp
@@ -1102,7 +1102,7 @@
 
       Instr.setDeleted();
       auto &LoweringContext = getTarget()->getContext();
-      LoweringContext.setInsertPoint(Instr);
+      LoweringContext.setInsertPoint(instToIterator(&Instr));
       LoweringContext.insert(ShuffleVector);
     }
   }