[pushed] Mark discriminants as artificial in gdb.dwarf2/variant.exp

[Tom Tromey]

While working on a variant part patch, I notcied that
gdb.dwarf2/variant.exp does not mark the discriminant members as
DW_AT_artificial.  However, it should, as this is what the real Rust
compiler does, and how the Rust language support is supposed to work.

gdb/testsuite/ChangeLog
2020-03-09  Tom Tromey  <tromey@adacore.com>

	* gdb.dwarf2/variant.exp: Mark discriminants as artificial.
---
 gdb/testsuite/ChangeLog              | 4 ++++
 gdb/testsuite/gdb.dwarf2/variant.exp | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/gdb/testsuite/gdb.dwarf2/variant.exp b/gdb/testsuite/gdb.dwarf2/variant.exp
index c0ae2e48bc2..0250fafc7f8 100644
--- a/gdb/testsuite/gdb.dwarf2/variant.exp
+++ b/gdb/testsuite/gdb.dwarf2/variant.exp
@@ -91,6 +91,7 @@ Dwarf::assemble $asm_file {
 		    discr_1_label: member {
 			{type :$uinteger_label}
 			{data_member_location 0 data1}
+			{artificial 1 DW_FORM_flag_present}
 		    }
 
 		    variant {
@@ -123,6 +124,7 @@ Dwarf::assemble $asm_file {
 		    discr_2_label: member {
 			{type :$uinteger_label}
 			{data_member_location 0 data1}
+			{artificial 1 DW_FORM_flag_present}
 		    }
 
 		    variant {
@@ -172,6 +174,7 @@ Dwarf::assemble $asm_file {
 		    discr_3_label: member {
 			{type :$int8_label}
 			{data_member_location 0 data1}
+			{artificial 1 DW_FORM_flag_present}
 		    }
 
 		    variant {
-- 
2.21.1