RoundEven implementation

Implementation for the roundEven glsl intrinsic function.
All dEQP roundEven tests pass.

Change-Id: I8b6f3704f03eea32b08a6c2dc318ecb99a01957d
Reviewed-on: https://swiftshader-review.googlesource.com/3382
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
diff --git a/src/Shader/PixelRoutine.cpp b/src/Shader/PixelRoutine.cpp
index dded202..d810f1b 100644
--- a/src/Shader/PixelRoutine.cpp
+++ b/src/Shader/PixelRoutine.cpp
@@ -3935,6 +3935,7 @@
 			case Shader::OPCODE_TRUNC:      trunc(d, s0);                                   break;
 			case Shader::OPCODE_FLOOR:      floor(d, s0);                                   break;
 			case Shader::OPCODE_ROUND:		round(d, s0);                                   break;
+			case Shader::OPCODE_ROUNDEVEN:	roundEven(d, s0);                               break;
 			case Shader::OPCODE_CEIL:       ceil(d, s0);                                    break;
 			case Shader::OPCODE_EXP2X:		exp2x(d, s0, pp);								break;
 			case Shader::OPCODE_EXP2:		exp2(d, s0, pp);								break;