Pass to verify generated machine code.

The following is checked:

* Operand counts: All explicit operands must be present.

* Register classes: All physical and virtual register operands must be
  compatible with the register class required by the instruction descriptor.

* Register live intervals: Registers must be defined only once, and must be
  defined before use.

The machine code verifier is enabled with the command-line option
'-verify-machineinstrs', or by defining the environment variable
LLVM_VERIFY_MACHINEINSTRS to the name of a file that will receive all the
verifier errors.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71918 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/Passes.h

@@ -196,6 +196,13 @@ namespace llvm {
   /// createStackProtectorPass - This pass adds stack protectors to functions.
   FunctionPass *createStackProtectorPass(const TargetLowering *tli);
 
+  /// createMachineVerifierPass - This pass verifies cenerated machine code
+  /// instructions for correctness.
+  ///
+  /// @param allowPhysDoubleDefs ignore double definitions of
+  ///        registers. Useful before LiveVariables has run.
+  FunctionPass *createMachineVerifierPass(bool allowDoubleDefs);
+
 } // End llvm namespace
 
 #endif