[Reassociate] Make one of the helper methods static because it doesn't use any class variables. NFC

llvm-svn: 305703
diff --git a/llvm/lib/Transforms/Scalar/Reassociate.cpp b/llvm/lib/Transforms/Scalar/Reassociate.cpp
index 4b543b6..4ce32e0 100644
--- a/llvm/lib/Transforms/Scalar/Reassociate.cpp
+++ b/llvm/lib/Transforms/Scalar/Reassociate.cpp
@@ -1628,8 +1628,8 @@
 ///   ((((x*y)*x)*y)*x) -> [(x, 3), (y, 2)]
 ///
 /// \returns Whether any factors have a power greater than one.
-bool ReassociatePass::collectMultiplyFactors(SmallVectorImpl<ValueEntry> &Ops,
-                                             SmallVectorImpl<Factor> &Factors) {
+static bool collectMultiplyFactors(SmallVectorImpl<ValueEntry> &Ops,
+                                   SmallVectorImpl<Factor> &Factors) {
   // FIXME: Have Ops be (ValueEntry, Multiplicity) pairs, simplifying this.
   // Compute the sum of powers of simplifiable factors.
   unsigned FactorPowerSum = 0;