Implement vector extract, insert, and swizzle.

Bug swiftshader:15

Change-Id: I81f88999e183ce3617d923249335ff02d6a9f1b1
Reviewed-on: https://swiftshader-review.googlesource.com/7396
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
diff --git a/src/Reactor/Main.cpp b/src/Reactor/Main.cpp
index a7aa820..e1887b5 100644
--- a/src/Reactor/Main.cpp
+++ b/src/Reactor/Main.cpp
@@ -50,6 +50,10 @@
 				z += (2 << i) - (i / 3);
 			}
 
+			Float4 v;
+			v.z = As<Float>(z);
+			z = As<Int>(Float(Float4(v.xzxx).y));
+
 			Int sum = x + y + z;
    
 			Return(sum);