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

llvm-svn: 247357
diff --git a/llvm/unittests/Support/BranchProbabilityTest.cpp b/llvm/unittests/Support/BranchProbabilityTest.cpp
index bbd4d4e..43bfa84 100644
--- a/llvm/unittests/Support/BranchProbabilityTest.cpp
+++ b/llvm/unittests/Support/BranchProbabilityTest.cpp
@@ -14,7 +14,7 @@
 using namespace llvm;
 
 namespace llvm {
-void PrintTo(const BranchProbability &P, ::std::ostream *os) {
+void PrintTo(BranchProbability P, ::std::ostream *os) {
   *os << P.getNumerator() << "/" << P.getDenominator();
 }
 }