cases: un-regress some notes

Since we now have source locations for reified types again, some error
notes have returned which were previously regressed by this branch.

test/cases/compile_errors/comptime_arg_to_generic_fn_callee_error.zig

@@ -18,3 +18,4 @@ pub export fn entry() void {
 // target=native
 //
 // :7:28: error: no field named 'c' in enum 'meta.FieldEnum(tmp.MyStruct)'
+// :?:?: note: enum declared here

test/cases/compile_errors/reify_type_for_tagged_union_with_extra_enum_field.zig

@@ -31,3 +31,5 @@ export fn entry() void {
 // target=native
 //
 // :13:16: error: enum fields missing in union
+// :1:13: note: field 'arst' missing, declared here
+// :1:13: note: enum declared here

test/cases/compile_errors/reify_type_for_tagged_union_with_extra_union_field.zig

@@ -31,3 +31,4 @@ export fn entry() void {
 // target=native
 //
 // :12:16: error: no field named 'arst' in enum 'tmp.Tag'
+// :1:13: note: enum declared here

test/cases/compile_errors/reify_type_for_tagged_union_with_no_enum_fields.zig

@@ -27,3 +27,4 @@ export fn entry() void {
 // target=native
 //
 // :9:16: error: no field named 'signed' in enum 'tmp.Tag'
+// :1:13: note: enum declared here

test/cases/compile_errors/reify_type_for_tagged_union_with_no_union_fields.zig

@@ -27,3 +27,6 @@ export fn entry() void {
 // target=native
 //
 // :12:16: error: enum fields missing in union
+// :1:13: note: field 'signed' missing, declared here
+// :1:13: note: field 'unsigned' missing, declared here
+// :1:13: note: enum declared here