[SILOptimizer] fix overrelease in KeyPathProjector

Because parentValue is the result of a setter projection, it is uninitalized and should not be destroyed again (see 1feead8)

Author: NobodyNada

lib/SILOptimizer/Utils/KeyPathProjector.cpp

@@ -430,8 +430,7 @@ class OptionalForceProjector : public ComponentProjector {
           break;
         }
         case AccessType::Set: {
-          // We can destroy the old value and write the new value in its place.
-          builder.createDestroyAddr(loc, optAddr);
+          // Write the new value directly into optAddr.
           auto objAddr = builder.createInitEnumDataAddr(loc, optAddr, someDecl, objType);
 
           callback(objAddr);