[libFuzzer] refactor the mutation functions so that they are now methods of a class. NFC

llvm-svn: 246808
diff --git a/llvm/lib/Fuzzer/FuzzerInterface.cpp b/llvm/lib/Fuzzer/FuzzerInterface.cpp
index 5df182e..231e757 100644
--- a/llvm/lib/Fuzzer/FuzzerInterface.cpp
+++ b/llvm/lib/Fuzzer/FuzzerInterface.cpp
@@ -20,9 +20,10 @@
 size_t FuzzerRandomLibc::Rand() { return rand(); }
 
 UserSuppliedFuzzer::UserSuppliedFuzzer()
-    : OwnRand(true), Rand(new FuzzerRandomLibc(0)) {}
+    : OwnRand(true), Rand(new FuzzerRandomLibc(0)), MD(*Rand) {}
 
-UserSuppliedFuzzer::UserSuppliedFuzzer(FuzzerRandomBase *Rand) : Rand(Rand) {}
+UserSuppliedFuzzer::UserSuppliedFuzzer(FuzzerRandomBase *Rand)
+    : Rand(Rand), MD(*Rand) {}
 
 UserSuppliedFuzzer::~UserSuppliedFuzzer() {
   if (OwnRand)