Move MinAlign to MathExtras.h.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43944 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/MathExtras.h

@@ -358,6 +358,13 @@ int IsNAN(double d);
 int IsInf(float f);
 int IsInf(double d);
 
+/// MinAlign - A and B are either alignments or offsets.  Return the minimum
+/// alignment that may be assumed after adding the two together.
+static inline unsigned MinAlign(unsigned A, unsigned B) {
+  // The largest power of 2 that divides both A and B.
+  return (A | B) & -(A | B);
+}
+
 } // End llvm namespace
 
 #endif