[LLD][ELF] Be more precise about Thumb state bit in ARM thunks

[peter.smith]

Summary

When we are able to reuse a Thumb thunk from ARM and vice versa the thumb state bit needs to be set to make sure that the bl is converted to a blx.

[peter.smith]

This is no longer required, it was implemented as part of D34036

ELF/Thunks.cpp

void ThumbV7ABSLongThunk<ELFT>::writeTo(uint8_t *Buf, ThunkSection &IS) const {
   Target->relocateOne(Buf, R_ARM_THM_MOVW_ABS_NC, S);
   Target->relocateOne(Buf + 4, R_ARM_THM_MOVT_ABS, S);
 }
 
 template <class ELFT>
 void ThumbV7ABSLongThunk<ELFT>::addSymbols(ThunkSection &IS) {
   this->ThunkSym = addSyntheticLocal<ELFT>(
       Saver.save("__Thumbv7ABSLongThunk_" + this->Destination.getName()),
-      STT_FUNC, this->Offset, size(), &IS);
+      STT_FUNC, this->Offset | 1, size(), &IS);
   addSyntheticLocal<ELFT>("$t", STT_NOTYPE, this->Offset, 0, &IS);
 }
 
 template <class ELFT>
 bool ThumbV7ABSLongThunk<ELFT>::compatibleWith(uint32_t RelocType) const {
   // ARM branch relocations can't use BLX
   return RelocType != R_ARM_JUMP24 && RelocType != R_ARM_PC24 &&
          RelocType != R_ARM_PLT32;

 void ThumbV7PILongThunk<ELFT>::writeTo(uint8_t *Buf, ThunkSection &IS) const {
   const uint8_t Data[] = {
       0x4f, 0xf6, 0xf4, 0x7c, // P:  movw ip,:lower16:S - (P + (L1-P) + 4)
       0xc0, 0xf2, 0x00, 0x0c, //     movt ip,:upper16:S - (P + (L1-P+4) + 4)
       0xfc, 0x44,             // L1: add  r12, pc
       0x60, 0x47,             //     bx   r12
   };
   uint64_t S = getARMThunkDestVA(this->Destination);
-  uint64_t P = this->ThunkSym->getVA();
+  uint64_t P = this->ThunkSym->getVA() & ~0x1;
   memcpy(Buf, Data, sizeof(Data));
   Target->relocateOne(Buf, R_ARM_THM_MOVW_PREL_NC, S - P - 12);
   Target->relocateOne(Buf + 4, R_ARM_THM_MOVT_PREL, S - P - 8);
 }
 
 template <class ELFT>
 void ThumbV7PILongThunk<ELFT>::addSymbols(ThunkSection &IS) {
   this->ThunkSym = addSyntheticLocal<ELFT>(
       Saver.save("__ThumbV7PILongThunk_" + this->Destination.getName()),
-      STT_FUNC, this->Offset, size(), &IS);
+      STT_FUNC, this->Offset | 1, size(), &IS);
   addSyntheticLocal<ELFT>("$t", STT_NOTYPE, this->Offset, 0, &IS);
 }
 
 template <class ELFT>
 bool ThumbV7PILongThunk<ELFT>::compatibleWith(uint32_t RelocType) const {
   // ARM branch relocations can't use BLX
   return RelocType != R_ARM_JUMP24 && RelocType != R_ARM_PC24 &&
          RelocType != R_ARM_PLT32;