[SOL] Revert to R_BPF_64_64 for global data object relocations

RBPF doesn't support R_BPF_64_ABS64 and R_BPF_64_64 correctly
represents relocation information for global data objects, so we can
use them without breaking the correctness of generated object files.

Author: dmakarov

lld/ELF/Arch/BPF.cpp

@@ -47,8 +47,6 @@ RelExpr BPF::getRelExpr(RelType type, const Symbol &s,
       return R_PC;
     case R_BPF_64_64:
       return R_ABS;
-    case R_BPF_64_ABS64:
-      return R_ADDEND;
     default:
       error(getErrorLocation(loc) + "unrecognized reloc " + toString(type));
   }
@@ -78,14 +76,6 @@ void BPF::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
       write32le(loc + 8 + 4, val >> 32);
       break;
     }
-    case R_BPF_64_ABS64: {
-      // The relocation type is used for normal 64-bit data. The
-      // actual to-be-relocated data is stored at r_offset and the
-      // read/write data bitsize is 64 (8 bytes). The relocation can
-      // be resolved with the symbol value plus implicit addend.
-      write64le(loc, val);
-      break;
-    }
     default:
       error(getErrorLocation(loc) + "unrecognized reloc " + toString(rel.type));
   }

llvm/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp

@@ -64,7 +64,7 @@ unsigned BPFELFObjectWriter::getRelocType(MCContext &Ctx, const MCValue &Target,
     // CALL instruction.
     return ELF::R_BPF_64_32;
   case FK_Data_8:
-    return ELF::R_BPF_64_ABS64;
+    return ELF::R_BPF_64_64;
   case FK_Data_4:
     if (const MCSymbolRefExpr *A = Target.getSymA()) {
       const MCSymbol &Sym = A->getSymbol();