[COFF] ARM64 support for COFFImportFile

A test will be committed separately in the lld repo.

Differential Revision: https://reviews.llvm.org/D35766

llvm-svn: 308951
diff --git a/llvm/lib/Object/COFFImportFile.cpp b/llvm/lib/Object/COFFImportFile.cpp
index d1f46fd..77cb625 100644
--- a/llvm/lib/Object/COFFImportFile.cpp
+++ b/llvm/lib/Object/COFFImportFile.cpp
@@ -36,6 +36,7 @@
   switch (Machine) {
   default:
     llvm_unreachable("unsupported machine");
+  case IMAGE_FILE_MACHINE_ARM64:
   case IMAGE_FILE_MACHINE_AMD64:
     return false;
   case IMAGE_FILE_MACHINE_ARMNT:
@@ -52,6 +53,8 @@
     return IMAGE_REL_AMD64_ADDR32NB;
   case IMAGE_FILE_MACHINE_ARMNT:
     return IMAGE_REL_ARM_ADDR32NB;
+  case IMAGE_FILE_MACHINE_ARM64:
+    return IMAGE_REL_ARM64_ADDR32NB;
   case IMAGE_FILE_MACHINE_I386:
     return IMAGE_REL_I386_DIR32NB;
   }