[PowerPC] 32-bit ELF PIC support

This adds initial support for PPC32 ELF PIC (Position Independent Code; the
-fPIC variety), thus rectifying a long-standing deficiency in the PowerPC
backend.

Patch by Justin Hibbits!

llvm-svn: 213427
diff --git a/llvm/lib/Object/ELF.cpp b/llvm/lib/Object/ELF.cpp
index df4dd5e..d999106 100644
--- a/llvm/lib/Object/ELF.cpp
+++ b/llvm/lib/Object/ELF.cpp
@@ -519,6 +519,7 @@
       LLVM_ELF_SWITCH_RELOC_TYPE_NAME(R_PPC_GOT16_LO);
       LLVM_ELF_SWITCH_RELOC_TYPE_NAME(R_PPC_GOT16_HI);
       LLVM_ELF_SWITCH_RELOC_TYPE_NAME(R_PPC_GOT16_HA);
+      LLVM_ELF_SWITCH_RELOC_TYPE_NAME(R_PPC_PLTREL24);
       LLVM_ELF_SWITCH_RELOC_TYPE_NAME(R_PPC_REL32);
       LLVM_ELF_SWITCH_RELOC_TYPE_NAME(R_PPC_TLS);
       LLVM_ELF_SWITCH_RELOC_TYPE_NAME(R_PPC_DTPMOD32);