Add CodeGenTarget::guessInstructionProperties.

Currently, TableGen just guesses instruction properties when it can't
infer them form patterns.

This adds a guessInstructionProperties flag to the instruction set
definition that will be used to disable guessing. The flag is intended
as a migration aid. It will be removed again when no more targets need
their properties guessed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162460 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/CodeGenTarget.h b/utils/TableGen/CodeGenTarget.h
index 2f8cee4..672b140 100644
--- a/utils/TableGen/CodeGenTarget.h
+++ b/utils/TableGen/CodeGenTarget.h
@@ -177,6 +177,10 @@
   ///
   bool isLittleEndianEncoding() const;
 
+  /// guessInstructionProperties - should we just guess unset instruction
+  /// properties?
+  bool guessInstructionProperties() const;
+
 private:
   void ComputeInstrsByEnum() const;
 };