[BOLT][NFC] Remove unreachable assertion

[ayermolo]

Summary?

[maksfb]

In D134094#3797084, @ayermolo wrote:

Summary?

No.

bolt/lib/Rewrite/RewriteInstance.cpp

for (auto ISym = SortedFileSymbols.begin(); ISym != SortedSymbolsEnd;
     } else {
       ErrorOr<BinarySection &> Section = BC->getSectionForAddress(Address);
       // Skip symbols from invalid sections
       if (!Section) {
         errs() << "BOLT-WARNING: " << UniqueName << " (0x"
                << Twine::utohexstr(Address) << ") does not have any section\n";
         continue;
       }
-      assert(Section && "section for functions must be registered");
 
       // Skip symbols from zero-sized sections.
       if (!Section->getSize())
         continue;
 
       BF = BC->createBinaryFunction(UniqueName, *Section, Address, SymbolSize);
       if (!IsSimple)
         BF->setSimple(false);