proc: bugfix: propagate signals we don't handle to inferior

Fixes #419 (partial)

proc/proc_unix_test.go

@@ -0,0 +1,31 @@
+// +build linux darwin
+
+package proc
+
+import (
+	"testing"
+	"time"
+	"syscall"
+
+	protest "github.com/derekparker/delve/proc/test"
+)
+
+func TestIssue419(t *testing.T) {
+	// SIGINT directed at the inferior should be passed along not swallowed by delve
+	withTestProcess("issue419", t, func(p *Process, fixture protest.Fixture) {
+		go func() {
+			for {
+				if p.Running() {
+					time.Sleep(2 * time.Second)
+					err := syscall.Kill(p.Pid, syscall.SIGINT)
+					assertNoError(err, t, "syscall.Kill")
+					return
+				}
+			}
+		}()
+		err := p.Continue()
+		if _, exited := err.(ProcessExitedError); !exited {
+			t.Fatalf("Unexpected error after Continue(): %v\n", err)
+		}
+	})
+}