[RISCV] MC layer support for the jump/branch instructions of the RVC extension

Differential Revision: https://reviews.llvm.org/D40002
    
Patch by Shiva Chen.

llvm-svn: 320038
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp
index e256156..ad53228 100644
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp
@@ -59,6 +59,10 @@
     return ELF::R_RISCV_JAL;
   case RISCV::fixup_riscv_branch:
     return ELF::R_RISCV_BRANCH;
+  case RISCV::fixup_riscv_rvc_jump:
+    return ELF::R_RISCV_RVC_JUMP;
+  case RISCV::fixup_riscv_rvc_branch:
+    return ELF::R_RISCV_RVC_BRANCH;
   }
 }