DI: Remove DW_TAG_arg_variable and DW_TAG_auto_variable

Remove the fake `DW_TAG_auto_variable` and `DW_TAG_arg_variable` tags,
using `DW_TAG_variable` in their place Stop exposing the `tag:` field at
all in the assembly format for `DILocalVariable`.

Most of the testcase updates were generated by the following sed script:

    find test/ -name "*.ll" -o -name "*.mir" |
    xargs grep -l 'DILocalVariable' |
    xargs sed -i '' \
      -e 's/tag: DW_TAG_arg_variable, //' \
      -e 's/tag: DW_TAG_auto_variable, //'

There were only a handful of tests in `test/Assembly` that I needed to
update by hand.

(Note: a follow-up could change `DILocalVariable::DILocalVariable()` to
set the tag to `DW_TAG_formal_parameter` instead of `DW_TAG_variable`
(as appropriate), instead of having that logic magically in the backend
in `DbgVariable`.  I've added a FIXME to that effect.)

llvm-svn: 243774
diff --git a/llvm/test/CodeGen/ARM/debug-info-arg.ll b/llvm/test/CodeGen/ARM/debug-info-arg.ll
index 84eae77..fcea788 100644
--- a/llvm/test/CodeGen/ARM/debug-info-arg.ll
+++ b/llvm/test/CodeGen/ARM/debug-info-arg.ll
@@ -37,7 +37,7 @@
 !2 = !DIFile(filename: "one.c", directory: "/Volumes/Athwagate/R10048772")
 !3 = !DISubroutineType(types: !4)
 !4 = !{null}
-!5 = !DILocalVariable(tag: DW_TAG_arg_variable, name: "this", line: 11, arg: 1, scope: !1, file: !2, type: !6)
+!5 = !DILocalVariable(name: "this", line: 11, arg: 1, scope: !1, file: !2, type: !6)
 !6 = !DIDerivedType(tag: DW_TAG_pointer_type, size: 32, align: 32, scope: !0, baseType: !7)
 !7 = !DICompositeType(tag: DW_TAG_structure_type, name: "tag_s", line: 5, size: 96, align: 32, file: !32, scope: !0, elements: !8)
 !8 = !{!9, !11, !12}
@@ -45,13 +45,13 @@
 !10 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
 !11 = !DIDerivedType(tag: DW_TAG_member, name: "y", line: 7, size: 32, align: 32, offset: 32, file: !32, scope: !7, baseType: !10)
 !12 = !DIDerivedType(tag: DW_TAG_member, name: "z", line: 8, size: 32, align: 32, offset: 64, file: !32, scope: !7, baseType: !10)
-!13 = !DILocalVariable(tag: DW_TAG_arg_variable, name: "c", line: 11, arg: 2, scope: !1, file: !2, type: !6)
-!14 = !DILocalVariable(tag: DW_TAG_arg_variable, name: "x", line: 11, arg: 3, scope: !1, file: !2, type: !15)
+!13 = !DILocalVariable(name: "c", line: 11, arg: 2, scope: !1, file: !2, type: !6)
+!14 = !DILocalVariable(name: "x", line: 11, arg: 3, scope: !1, file: !2, type: !15)
 !15 = !DIDerivedType(tag: DW_TAG_typedef, name: "UInt64", line: 1, file: !32, scope: !0, baseType: !16)
 !16 = !DIBasicType(tag: DW_TAG_base_type, name: "long long unsigned int", size: 64, align: 32, encoding: DW_ATE_unsigned)
-!17 = !DILocalVariable(tag: DW_TAG_arg_variable, name: "y", line: 11, arg: 4, scope: !1, file: !2, type: !15)
-!18 = !DILocalVariable(tag: DW_TAG_arg_variable, name: "ptr1", line: 11, arg: 5, scope: !1, file: !2, type: !6)
-!19 = !DILocalVariable(tag: DW_TAG_arg_variable, name: "ptr2", line: 11, arg: 6, scope: !1, file: !2, type: !6)
+!17 = !DILocalVariable(name: "y", line: 11, arg: 4, scope: !1, file: !2, type: !15)
+!18 = !DILocalVariable(name: "ptr1", line: 11, arg: 5, scope: !1, file: !2, type: !6)
+!19 = !DILocalVariable(name: "ptr2", line: 11, arg: 6, scope: !1, file: !2, type: !6)
 !20 = !DILocation(line: 11, column: 24, scope: !1)
 !21 = !DILocation(line: 11, column: 44, scope: !1)
 !22 = !DILocation(line: 11, column: 54, scope: !1)