Recover elf32-bigmips support in LLD

[vit9696]

Summary

This fixes a 7.0 -> 8.0 regression when parsing OUTPUT_FORMAT("elf32-bigmips"); directive in ldscripts.

I request this to be backported to LLD 8.0, as it is a regression breaking ldscripts that worked fine with LLD 7.0.

[ruiu]

Can you merge your recent patches that adds new entries to this place into a single patch, add tests to lld/test/ELF/emulation-ppc.s, and then repost?

[vit9696]

Sure, superseded by D58005.

lld/ELF/ScriptParser.cpp

return StringSwitch<std::pair<ELFKind, uint16_t>>(S)
       .Case("elf32-littlearm", {ELF32LEKind, EM_ARM})
       .Case("elf32-x86-64", {ELF32LEKind, EM_X86_64})
       .Case("elf64-aarch64", {ELF64LEKind, EM_AARCH64})
       .Case("elf64-littleaarch64", {ELF64LEKind, EM_AARCH64})
       .Case("elf32-powerpc", {ELF32BEKind, EM_PPC})
       .Case("elf64-powerpc", {ELF64BEKind, EM_PPC64})
       .Case("elf64-powerpcle", {ELF64LEKind, EM_PPC64})
       .Case("elf64-x86-64", {ELF64LEKind, EM_X86_64})
-      .Case("elf32-tradbigmips", {ELF32BEKind, EM_MIPS})
+      .Cases("elf32-tradbigmips", "elf32-bigmips", {ELF32BEKind, EM_MIPS})
       .Case("elf32-ntradbigmips", {ELF32BEKind, EM_MIPS})
       .Case("elf32-tradlittlemips", {ELF32LEKind, EM_MIPS})
       .Case("elf32-ntradlittlemips", {ELF32LEKind, EM_MIPS})
       .Case("elf64-tradbigmips", {ELF64BEKind, EM_MIPS})
       .Case("elf64-tradlittlemips", {ELF64LEKind, EM_MIPS})
       .Default({ELFNoneKind, EM_NONE});
 }