Pass BranchProbability/BlockMass by value instead of const& as they are small. NFC.

llvm-svn: 247357
diff --git a/llvm/lib/Support/BlockFrequency.cpp b/llvm/lib/Support/BlockFrequency.cpp
index 6f7e341..e901fe6 100644
--- a/llvm/lib/Support/BlockFrequency.cpp
+++ b/llvm/lib/Support/BlockFrequency.cpp
@@ -18,24 +18,24 @@
 
 using namespace llvm;
 
-BlockFrequency &BlockFrequency::operator*=(const BranchProbability &Prob) {
+BlockFrequency &BlockFrequency::operator*=(BranchProbability Prob) {
   Frequency = Prob.scale(Frequency);
   return *this;
 }
 
 const BlockFrequency
-BlockFrequency::operator*(const BranchProbability &Prob) const {
+BlockFrequency::operator*(BranchProbability Prob) const {
   BlockFrequency Freq(Frequency);
   Freq *= Prob;
   return Freq;
 }
 
-BlockFrequency &BlockFrequency::operator/=(const BranchProbability &Prob) {
+BlockFrequency &BlockFrequency::operator/=(BranchProbability Prob) {
   Frequency = Prob.scaleByInverse(Frequency);
   return *this;
 }
 
-BlockFrequency BlockFrequency::operator/(const BranchProbability &Prob) const {
+BlockFrequency BlockFrequency::operator/(BranchProbability Prob) const {
   BlockFrequency Freq(Frequency);
   Freq /= Prob;
   return Freq;