[ELF] Support a few more SPARCv9 relocations

Implemented a bunch of relocations found in binaries with medium/large code model and the Local-Exec TLS model. The binaries link and run fine in Qemu.
In addition, the emulation `elf64_sparc` is now recognized.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D77672

lld/ELF/ScriptParser.cpp

@@ -404,6 +404,7 @@ static std::pair<ELFKind, uint16_t> parseBfdName(StringRef s) {
       .Case("elf64-tradlittlemips", {ELF64LEKind, EM_MIPS})
       .Case("elf32-littleriscv", {ELF32LEKind, EM_RISCV})
       .Case("elf64-littleriscv", {ELF64LEKind, EM_RISCV})
+      .Case("elf64-sparc", {ELF64BEKind, EM_SPARCV9})
       .Default({ELFNoneKind, EM_NONE});
 }