[C++11] Mark the target fast isel classes as 'final' so that the compiler can de-virtualize some of the internal calls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204123 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/PowerPC/PPCFastISel.cpp

@@ -80,7 +80,7 @@ typedef struct Address {
    }
 } Address;
 
-class PPCFastISel : public FastISel {
+class PPCFastISel final : public FastISel {
 
   const TargetMachine &TM;
   const TargetInstrInfo &TII;