stage2: fix `@call` when used in a comptime or nosuspend block

`@call` allows specifying the modifier explicitly, however it can still
appear in a context that overrides the modifier. This commit adds flags
to the BuiltinCall ZIR encoding. Since we have unused bits I also threw
in the ensure_result_used mechanism.

I also deleted a behavior test that was checking for bound function
behavior where I think stage2 behavior is correct and stage1 behavior
is incorrect.

1 files changed, 9 insertions, 22 deletions

diff --git a/test/behavior/call.zig b/test/behavior/call.zig
index 27d0bbf1d6..0297582234 100644
--- a/test/behavior/call.zig
+++ b/test/behavior/call.zig
@@ -19,7 +19,11 @@ test "super basic invocations" {
 }
 
 test "basic invocations" {
-    if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
 
     const foo = struct {
         fn foo() i32 {
@@ -41,7 +45,10 @@ test "basic invocations" {
     }
     {
         // call of non comptime-known function
-        var alias_foo = foo;
+        var alias_foo = switch (builtin.zig_backend) {
+            .stage1 => foo,
+            else => &foo,
+        };
         try expect(@call(.{ .modifier = .no_async }, alias_foo, .{}) == 1234);
         try expect(@call(.{ .modifier = .never_tail }, alias_foo, .{}) == 1234);
         try expect(@call(.{ .modifier = .never_inline }, alias_foo, .{}) == 1234);
@@ -79,26 +86,6 @@ test "tuple parameters" {
     }
 }
 
-test "comptime call with bound function as parameter" {
-    if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
-
-    const S = struct {
-        fn ReturnType(func: anytype) type {
-            return switch (@typeInfo(@TypeOf(func))) {
-                .BoundFn => |info| info,
-                else => unreachable,
-            }.return_type orelse void;
-        }
-
-        fn call_me_maybe() ?i32 {
-            return 123;
-        }
-    };
-
-    var inst: S = undefined;
-    try expectEqual(?i32, S.ReturnType(inst.call_me_maybe));
-}
-
 test "result location of function call argument through runtime condition and struct init" {
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO