[ELF] Add elf64lppc emulation.

[ruiu]

I think this patch should be checked in with a trivial test case that generates a minimal binary file for ppc64le.

[MaskRay]

Add elf64lppc to emulation.s

[ruiu]

LGTM

But I think further efforts should be made with a coordination with other people who are working on PPC, so that no duplicate efforts are made.

[MaskRay]

In D44264#1033235, @ruiu wrote:

LGTM

But I think further efforts should be made with a coordination with other people who are working on PPC, so that no duplicate efforts are made.

Thx.
e.g. coordinate with PPC, ARM, HPPA, METAG people for the --stub-group-size= option..

lld/trunk/ELF/Driver.cpp

std::pair<ELFKind, uint16_t> Ret =
           .Cases("armelf", "armelf_linux_eabi", {ELF32LEKind, EM_ARM})
           .Case("elf32_x86_64", {ELF32LEKind, EM_X86_64})
           .Cases("elf32btsmip", "elf32btsmipn32", {ELF32BEKind, EM_MIPS})
           .Cases("elf32ltsmip", "elf32ltsmipn32", {ELF32LEKind, EM_MIPS})
           .Case("elf32ppc", {ELF32BEKind, EM_PPC})
           .Case("elf64btsmip", {ELF64BEKind, EM_MIPS})
           .Case("elf64ltsmip", {ELF64LEKind, EM_MIPS})
           .Case("elf64ppc", {ELF64BEKind, EM_PPC64})
+          .Case("elf64lppc", {ELF64LEKind, EM_PPC64})
           .Cases("elf_amd64", "elf_x86_64", {ELF64LEKind, EM_X86_64})
           .Case("elf_i386", {ELF32LEKind, EM_386})
           .Case("elf_iamcu", {ELF32LEKind, EM_IAMCU})
           .Default({ELFNoneKind, EM_NONE});
 
   if (Ret.first == ELFNoneKind)
     error("unknown emulation: " + Emul);
   return std::make_tuple(Ret.first, Ret.second, OSABI);

lld/trunk/test/ELF/emulation.s

 # PPC64-NEXT:   HeaderSize: 64
 # PPC64-NEXT:   ProgramHeaderEntrySize: 56
 # PPC64-NEXT:   ProgramHeaderCount:
 # PPC64-NEXT:   SectionHeaderEntrySize: 64
 # PPC64-NEXT:   SectionHeaderCount:
 # PPC64-NEXT:   StringTableSectionIndex:
 # PPC64-NEXT: }
 
+# RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %tppc64le
+# RUN: ld.lld -m elf64lppc %tppc64le -o %t2ppc64le
+# RUN: llvm-readobj -file-headers %t2ppc64le | FileCheck --check-prefix=PPC64LE %s
+# RUN: ld.lld %tppc64le -o %t3ppc64le
+# RUN: llvm-readobj -file-headers %t3ppc64le | FileCheck --check-prefix=PPC64LE %s
+# PPC64LE:      ElfHeader {
+# PPC64LE-NEXT:   Ident {
+# PPC64LE-NEXT:     Magic: (7F 45 4C 46)
+# PPC64LE-NEXT:     Class: 64-bit (0x2)
+# PPC64LE-NEXT:     DataEncoding: LittleEndian (0x1)
+# PPC64LE-NEXT:     FileVersion: 1
+# PPC64LE-NEXT:     OS/ABI: SystemV (0x0)
+# PPC64LE-NEXT:     ABIVersion: 0
+# PPC64LE-NEXT:     Unused: (00 00 00 00 00 00 00)
+# PPC64LE-NEXT:   }
+# PPC64LE-NEXT:   Type: Executable (0x2)
+# PPC64LE-NEXT:   Machine: EM_PPC64 (0x15)
+# PPC64LE-NEXT:   Version: 1
+# PPC64LE-NEXT:   Entry:
+# PPC64LE-NEXT:   ProgramHeaderOffset: 0x40
+# PPC64LE-NEXT:   SectionHeaderOffset:
+# PPC64LE-NEXT:   Flags [ (0x0)
+# PPC64LE-NEXT:   ]
+# PPC64LE-NEXT:   HeaderSize: 64
+# PPC64LE-NEXT:   ProgramHeaderEntrySize: 56
+# PPC64LE-NEXT:   ProgramHeaderCount:
+# PPC64LE-NEXT:   SectionHeaderEntrySize: 64
+# PPC64LE-NEXT:   SectionHeaderCount:
+# PPC64LE-NEXT:   StringTableSectionIndex:
+# PPC64LE-NEXT: }
+
 # RUN: llvm-mc -filetype=obj -triple=mips-unknown-linux %s -o %tmips
 # RUN: ld.lld -m elf32btsmip -e _start %tmips -o %t2mips
 # RUN: llvm-readobj -file-headers %t2mips | FileCheck --check-prefix=MIPS %s
 # RUN: ld.lld %tmips -e _start -o %t3mips
 # RUN: llvm-readobj -file-headers %t3mips | FileCheck --check-prefix=MIPS %s
 # MIPS:      ElfHeader {
 # MIPS-NEXT:   Ident {
 # MIPS-NEXT:     Magic: (7F 45 4C 46)