MC: make WinEH opcode an opaque value

This makes the opcode an opaque value (unsigned int) rather than the
enumeration.  This permits the use of target specific operands.

Split out the generic type into a MCWinEH header and add a supporting
MCWin64EH::Instruction to abstract out the selection of the opcode and
construction of the actual instruction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213221 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCWinEH.h

@@ -0,0 +1,29 @@
+//===- MCWinEH.h - Windows Unwinding Support --------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_MC_MCWINEH_H
+#define LLVM_MC_MCWINEH_H
+
+namespace llvm {
+class MCSymbol;
+
+namespace WinEH {
+struct Instruction {
+  const MCSymbol *Label;
+  const unsigned Offset;
+  const unsigned Register;
+  const unsigned Operation;
+
+  Instruction(unsigned Op, MCSymbol *L, unsigned Reg, unsigned Off)
+    : Label(L), Offset(Off), Register(Reg), Operation(Op) {}
+};
+}
+}
+
+#endif