Fix r353771 to target linux only (split-dwarf isn't supported on macho)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353785 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/DebugInfo/X86/gmlt-no-split-dwarf-inlining-empty.ll b/test/DebugInfo/X86/gmlt-no-split-dwarf-inlining-empty.ll
index 0411819..e540492 100644
--- a/test/DebugInfo/X86/gmlt-no-split-dwarf-inlining-empty.ll
+++ b/test/DebugInfo/X86/gmlt-no-split-dwarf-inlining-empty.ll
@@ -7,6 +7,8 @@
 
 ; CHECK-NOT: .debug_{{.*}}.dwo
 
+target triple = "x86_64-pc-linux"
+
 define dso_local void @f1() !dbg !7 {
 entry:
   ret void, !dbg !9