Rename SmallVectorTemplateCommon::reserveForAndGetAddress() to
reserveForParamAndGetAddress(), clarifying that it should only be called
for "parameter values". Use that semantic information to skip calling
SmallVector::isReferenceToStorage() when TakesParamByValue (which is
This has no functional change, but likely speeds up operations like
SmallVector::push_back() for small POD-like types. Even if the
optimizer was smart enough to eliminate the call, this speeds up
compile-time since the call is now trivially dead.