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

This reverts commit 289920 (again).
I forgot to implement a Bitcode upgrade for the case where a DIGlobalVariable
has not DIExpression. Unfortunately it is not possible to safely upgrade
these variables without adding a flag to the bitcode record indicating which
version they are.
My plan of record is to roll the planned follow-up patch that adds a
unit: field to DIGlobalVariable into this patch before recomitting.
This way we only need one Bitcode upgrade for both changes (with a
version flag in the bitcode record to safely distinguish the record
formats).

Sorry for the churn!

llvm-svn: 289982

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/test/DebugInfo/Generic/gvn.ll b/llvm/test/DebugInfo/Generic/gvn.ll
index 2120ed72b07..6de5b174891 100644
--- a/llvm/test/DebugInfo/Generic/gvn.ll
+++ b/llvm/test/DebugInfo/Generic/gvn.ll
@@ -81,8 +81,8 @@ attributes #3 = { nounwind }
 !13 = !DISubroutineType(types: !14)
 !14 = !{null}
 !15 = !{!16, !17}
-!16 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "a", scope: !0, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true))
-!17 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "b", scope: !0, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true))
+!16 = !DIGlobalVariable(name: "a", scope: !0, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true)
+!17 = !DIGlobalVariable(name: "b", scope: !0, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true)
 !18 = !{i32 2, !"Dwarf Version", i32 2}
 !19 = !{i32 2, !"Debug Info Version", i32 3}
 !20 = !{!"clang version 3.8.0 (trunk 245562) (llvm/trunk 245569)"}