[LLD][ELF] Add call to assignAddresses() before createThunks() [NFC]

[peter.smith]

Summary

In preparation for the addition of rangeThunks() calculate the addresses of all the inputSections so that ThunkSections can be inserted at the right place.
This is range thunks patch 5/11 it depends on: D34344 and D34345

ELF/Writer.cpp

template <class ELFT> void Writer<ELFT>::finalizeSections() {
   if (Target->NeedsThunks) {
     // FIXME: only ARM Interworking and Mips LA25 Thunks are implemented,
     // these
     // do not require address information. To support range extension Thunks
     // we need to assign addresses so that we can tell if jump instructions
     // are out of range. This will need to turn into a loop that converges
     // when no more Thunks are added
     ThunkCreator TC;
+    Script->assignAddresses();
     if (TC.createThunks(OutputSectionCommands)) {
       applySynthetic({InX::MipsGot},
                      [](SyntheticSection *SS) { SS->updateAllocSize(); });
       if (TC.createThunks(OutputSectionCommands))
         fatal("All non-range thunks should be created in first call");
     }
   }