test: delete old stage1 compile_errors tests

generic_function_returning_opaque_type.zig was salvaged as it's still worth
having.

test/cases/README.md

@@ -84,6 +84,5 @@ path will be prepended as a prefix on the test case name.
 Possible backends are:
 
  * `auto`: the default; compiler picks the backend based on robustness.
- * `stage1`: equivalent to `-fstage1`.
  * `selfhosted`: equivalent to passing `-fno-llvm -fno-lld`.
  * `llvm`: equivalent to `-fllvm`.

test/cases/compile_errors/generic_function_returning_opaque_type.zig

@@ -0,0 +1,16 @@
+fn generic(comptime T: type) T {
+    return undefined;
+}
+const MyOpaque = opaque {};
+export fn foo() void {
+    _ = generic(MyOpaque);
+}
+export fn bar() void {
+    _ = generic(anyopaque);
+}
+
+// error
+//
+// :1:30: error: opaque return type 'tmp.MyOpaque' not allowed
+// :4:18: note: opaque declared here
+// :1:30: error: opaque return type 'anyopaque' not allowed

test/cases/compile_errors/stage1/obj/call_with_new_stack_on_unsupported_target.zig

@@ -1,11 +0,0 @@
-var buf: [10]u8 align(16) = undefined;
-export fn entry() void {
-    @call(.{ .stack = &buf }, foo, .{});
-}
-fn foo() void {}
-
-// error
-// backend=stage1
-// target=wasm32-wasi-none
-//
-// tmp.zig:3:5: error: target arch 'wasm32' does not support calling with a new stack

test/cases/compile_errors/stage1/obj/generic_fn_as_parameter_without_comptime_keyword.zig

@@ -1,11 +0,0 @@
-fn f(_: fn (anytype) void) void {}
-fn g(_: anytype) void {}
-export fn entry() void {
-    f(g);
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:1:9: error: parameter of type 'fn (anytype) anytype' must be declared comptime

test/cases/compile_errors/stage1/obj/generic_function_returning_opaque_type.zig

@@ -1,25 +0,0 @@
-const FooType = opaque {};
-fn generic(comptime T: type) !T {
-    return undefined;
-}
-export fn bar() void {
-    _ = generic(FooType);
-}
-export fn bav() void {
-    _ = generic(@TypeOf(null));
-}
-export fn baz() void {
-    _ = generic(@TypeOf(undefined));
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:6:16: error: call to generic function with Opaque return type 'FooType' not allowed
-// tmp.zig:2:1: note: function declared here
-// tmp.zig:1:1: note: type declared here
-// tmp.zig:9:16: error: call to generic function with Null return type '@Type(.Null)' not allowed
-// tmp.zig:2:1: note: function declared here
-// tmp.zig:12:16: error: call to generic function with Undefined return type '@Type(.Undefined)' not allowed
-// tmp.zig:2:1: note: function declared here

test/cases/compile_errors/stage1/obj/generic_function_where_return_type_is_self-referenced.zig

@@ -1,13 +0,0 @@
-fn Foo(comptime T: type) Foo(T) {
-    return struct { x: T };
-}
-export fn entry() void {
-    const t = Foo(u32){ .x = 1 };
-    _ = t;
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:1:29: error: evaluation exceeded 1000 backwards branches

test/cases/compile_errors/stage1/obj/unsupported_modifier_at_start_of_asm_output_constraint.zig

@@ -1,14 +0,0 @@
-export fn foo() void {
-    var bar: u32 = 3;
-    asm volatile (""
-        : [baz] "+r" (bar),
-        :
-        : ""
-    );
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:3:5: error: invalid modifier starting output constraint for 'baz': '+', only '=' is supported. Compiler TODO: see https://github.com/ziglang/zig/issues/215

test/cases/compile_errors/stage1/obj/variable_in_inline_assembly_template_cannot_be_found.zig

@@ -1,12 +0,0 @@
-export fn entry() void {
-    var sp = asm volatile ("mov %[foo], sp"
-        : [bar] "=r" (-> usize),
-    );
-    _ = &sp;
-}
-
-// error
-// backend=stage1
-// target=x86_64-linux-gnu
-//
-// tmp.zig:2:14: error: could not find 'foo' in the inputs or outputs

test/src/Cases.zig

@@ -28,7 +28,6 @@ pub const DepModule = struct {
 pub const Backend = enum {
     /// Test does not care which backend is used; compiler gets to pick the default.
     auto,
-    stage1,
     selfhosted,
     llvm,
 };
@@ -623,7 +622,6 @@ pub fn lowerToBuildSteps(
         const would_use_llvm = @import("../tests.zig").wouldUseLlvm(
             switch (case.backend) {
                 .auto => null,
-                .stage1 => continue,
                 .selfhosted => false,
                 .llvm => true,
             },
@@ -699,7 +697,6 @@ pub fn lowerToBuildSteps(
 
         switch (case.backend) {
             .auto => {},
-            .stage1 => continue,
             .selfhosted => {
                 artifact.use_llvm = false;
                 artifact.use_lld = false;