vendor: update buildkit to v0.8

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/moby/buildkit/frontend/gateway/client/client.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"context"
+	"io"
 
 	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/solver/pb"
@@ -16,6 +17,64 @@ type Client interface {
 	ResolveImageConfig(ctx context.Context, ref string, opt llb.ResolveImageConfigOpt) (digest.Digest, []byte, error)
 	BuildOpts() BuildOpts
 	Inputs(ctx context.Context) (map[string]llb.State, error)
+	NewContainer(ctx context.Context, req NewContainerRequest) (Container, error)
+}
+
+// NewContainerRequest encapsulates the requirements for a client to define a
+// new container, without defining the initial process.
+type NewContainerRequest struct {
+	Mounts      []Mount
+	NetMode     pb.NetMode
+	Platform    *pb.Platform
+	Constraints *pb.WorkerConstraints
+}
+
+// Mount allows clients to specify a filesystem mount. A Reference to a
+// previously solved Result is required.
+type Mount struct {
+	Selector  string
+	Dest      string
+	ResultID  string
+	Ref       Reference
+	Readonly  bool
+	MountType pb.MountType
+	CacheOpt  *pb.CacheOpt
+	SecretOpt *pb.SecretOpt
+	SSHOpt    *pb.SSHOpt
+}
+
+// Container is used to start new processes inside a container and release the
+// container resources when done.
+type Container interface {
+	Start(context.Context, StartRequest) (ContainerProcess, error)
+	Release(context.Context) error
+}
+
+// StartRequest encapsulates the arguments to define a process within a
+// container.
+type StartRequest struct {
+	Args           []string
+	Env            []string
+	User           string
+	Cwd            string
+	Tty            bool
+	Stdin          io.ReadCloser
+	Stdout, Stderr io.WriteCloser
+	SecurityMode   pb.SecurityMode
+}
+
+// WinSize is same as executor.WinSize, copied here to prevent circular package
+// dependencies.
+type WinSize struct {
+	Rows uint32
+	Cols uint32
+}
+
+// ContainerProcess represents a process within a container.
+type ContainerProcess interface {
+	Wait() error
+	Resize(ctx context.Context, size WinSize) error
+	// TODO Signal(ctx context.Context, sig os.Signal)
 }
 
 type Reference interface {
@@ -46,6 +105,7 @@ type StatRequest struct {
 
 // SolveRequest is same as frontend.SolveRequest but avoiding dependency
 type SolveRequest struct {
+	Evaluate       bool
 	Definition     *pb.Definition
 	Frontend       string
 	FrontendOpt    map[string]string