Implement intrinsics for loading/storing subvectors.

This enables emulating 64-bit and 32-bit vectors using 128-bit
vectors internally (x86 only for now). Note that these Intrinsics
are not part of the PNaCL specification.

BUG=swiftshader:15

Change-Id: I61a666243832c2856e60eb477d42a72dec07d01d
Reviewed-on: https://chromium-review.googlesource.com/392246
Reviewed-by: Jim Stichnoth <stichnot@chromium.org>
Tested-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/IceTargetLoweringARM32.cpp b/src/IceTargetLoweringARM32.cpp
index 7564652..4577997 100644
--- a/src/IceTargetLoweringARM32.cpp
+++ b/src/IceTargetLoweringARM32.cpp
@@ -5279,6 +5279,14 @@
   case Intrinsics::Trap:
     _trap();
     return;
+  case Intrinsics::LoadSubVector: {
+    UnimplementedLoweringError(this, Instr);
+    return;
+  }
+  case Intrinsics::StoreSubVector: {
+    UnimplementedLoweringError(this, Instr);
+    return;
+  }
   case Intrinsics::UnknownIntrinsic:
     Func->setError("Should not be lowering UnknownIntrinsic");
     return;