ELF: Add --build-id=sha1 option.

llvm-svn: 265748
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 0f0f771..3188d73 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -343,6 +343,8 @@
     StringRef S = Arg->getValue();
     if (S == "md5") {
       Config->BuildId = BuildIdKind::Md5;
+    } else if (S == "sha1") {
+      Config->BuildId = BuildIdKind::Sha1;
     } else
       error("unknown --build-id style: " + S);
   }