Use Delve v0.12.1 instead of master

vendor/github.com/derekparker/delve/proc/arch.go

@@ -0,0 +1,79 @@
+package proc
+
+import "runtime"
+
+// Arch defines an interface for representing a
+// CPU architecture.
+type Arch interface {
+	SetGStructOffset(ver GoVersion, iscgo bool)
+	PtrSize() int
+	BreakpointInstruction() []byte
+	BreakpointSize() int
+	GStructOffset() uint64
+}
+
+// AMD64 represents the AMD64 CPU architecture.
+type AMD64 struct {
+	ptrSize                 int
+	breakInstruction        []byte
+	breakInstructionLen     int
+	gStructOffset           uint64
+	hardwareBreakpointUsage []bool
+}
+
+// AMD64Arch returns an initialized AMD64
+// struct.
+func AMD64Arch() *AMD64 {
+	var breakInstr = []byte{0xCC}
+
+	return &AMD64{
+		ptrSize:                 8,
+		breakInstruction:        breakInstr,
+		breakInstructionLen:     len(breakInstr),
+		hardwareBreakpointUsage: make([]bool, 4),
+	}
+}
+
+// SetGStructOffset sets the offset of the G struct on the AMD64
+// arch struct. The offset is dependent on the Go compiler Version
+// and whether or not the target program was externally linked.
+func (a *AMD64) SetGStructOffset(ver GoVersion, isextld bool) {
+	switch runtime.GOOS {
+	case "darwin":
+		a.gStructOffset = 0x8a0
+	case "linux":
+		a.gStructOffset = 0xfffffffffffffff0
+		if isextld || ver.AfterOrEqual(GoVersion{1, 5, -1, 2, 0}) || ver.IsDevel() {
+			a.gStructOffset += 8
+		}
+	case "windows":
+		// Use ArbitraryUserPointer (0x28) as pointer to pointer
+		// to G struct per:
+		// https://golang.org/src/runtime/cgo/gcc_windows_amd64.c
+		a.gStructOffset = 0x28
+	}
+}
+
+// PtrSize returns the size of a pointer
+// on this architecture.
+func (a *AMD64) PtrSize() int {
+	return a.ptrSize
+}
+
+// BreakpointInstruction returns the Breakpoint
+// instruction for this architecture.
+func (a *AMD64) BreakpointInstruction() []byte {
+	return a.breakInstruction
+}
+
+// BreakpointSize returns the size of the
+// breakpoint instruction on this architecture.
+func (a *AMD64) BreakpointSize() int {
+	return a.breakInstructionLen
+}
+
+// GStructOffset returns the offset of the G
+// struct in thread local storage.
+func (a *AMD64) GStructOffset() uint64 {
+	return a.gStructOffset
+}