Update internal Pipe wiring - fixes #615" (#616)

Replace ambiguous bi-connect ("<>") with mono-connect (":=") for internal Pipe wiring.
(cherry picked from commit 0d121a2)

bump version

build.sbt

@@ -15,7 +15,7 @@ lazy val customUnidocSettings = unidocSettings ++ Seq (
 
 lazy val commonSettings = Seq (
   organization := "edu.berkeley.cs",
-  version := "3.0-SNAPSHOT_2017-05-16",
+  version := "3.0-SNAPSHOT_2017-05-25",
   git.remoteRepo := "git@github.com:ucb-bar/chisel3.git",
   scalaVersion := "2.11.7",
   autoAPIMappings := true,

src/main/scala/chisel3/util/Valid.scala

@@ -38,8 +38,8 @@ object Pipe
   def apply[T <: Data](enqValid: Bool, enqBits: T, latency: Int)(implicit compileOptions: CompileOptions): Valid[T] = {
     if (latency == 0) {
       val out = Wire(Valid(enqBits))
-      out.valid <> enqValid
-      out.bits <> enqBits
+      out.valid := enqValid
+      out.bits := enqBits
       out
     } else {
       val v = RegNext(enqValid, false.B)

src/test/scala/chiselTests/ConnectSpec.scala

@@ -3,7 +3,7 @@
 package chiselTests
 
 import chisel3._
-import chisel3.experimental.{FixedPoint, Analog}
+import chisel3.experimental.{Analog, FixedPoint}
 import chisel3.testers.BasicTester
 
 abstract class CrossCheck extends Bundle {
@@ -19,6 +19,17 @@ class CrossConnects(inType: Data, outType: Data) extends Module {
   io.out := io.in
 }
 
+class PipeInternalWires extends Module {
+  import chisel3.util.Pipe
+  val io = IO(new Bundle {
+    val a = Input(Bool())
+    val b = Input(UInt(32.W))
+  })
+  val pipe = Module(new Pipe(UInt(32.W), 32))
+  pipe.io.enq.valid <> io.a
+  pipe.io.enq.bits <> io.b
+}
+
 class CrossConnectTester(inType: Data, outType: Data) extends BasicTester {
   val dut = Module(new CrossConnects(inType, outType))
   stop()
@@ -82,4 +93,7 @@ class ConnectSpec extends ChiselPropSpec {
   property("SInt := Analog should fail") {
     intercept[ChiselException]{ new CrossConnectTester(SInt(16.W), Analog(16.W)) }
   }
+  property("Pipe internal connections should succeed") {
+    elaborate( new PipeInternalWires)
+  }
 }