Revert "[IR] Remove the DIExpression field from DIGlobalVariable."

This reverts commit 289902 while investigating bot berakage.

llvm-svn: 289906
diff --git a/llvm/test/DebugInfo/ARM/big-endian-bitfield.ll b/llvm/test/DebugInfo/ARM/big-endian-bitfield.ll
index bbe7bf9..664e54c 100644
--- a/llvm/test/DebugInfo/ARM/big-endian-bitfield.ll
+++ b/llvm/test/DebugInfo/ARM/big-endian-bitfield.ll
@@ -22,7 +22,7 @@
 !1 = !DIFile(filename: "bitfield.c", directory: "/Volumes/Data/llvm")
 !2 = !{}
 !3 = !{!4}
-!4 = distinct !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "s", scope: !0, file: !1, line: 6, type: !5, isLocal: false, isDefinition: true))
+!4 = distinct !DIGlobalVariable(name: "s", scope: !0, file: !1, line: 6, type: !5, isLocal: false, isDefinition: true)
 !5 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "S", file: !1, line: 1, size: 32, elements: !6)
 !6 = !{!7, !9, !10, !11}
 ; CHECK: DW_TAG_member