AstGen: allow closure over known-runtime values within @TypeOf

AstGen emits an error when a closure over a known-runtime value crosses
a namespace boundary. This usually makes sense: however, this usage is
actually valid if the capture is within a `@TypeOf` operand. Sema
already has a special case to allow such closure within `@TypeOf` when
AstGen could not determine a value to be runtime-known. This commit
simply introduces analagous logic to AstGen to allow `var`s to cross
namespace boundaries within `@TypeOf`.

1 files changed, 10 insertions, 0 deletions

diff --git a/test/behavior/eval.zig b/test/behavior/eval.zig
index 35cfab9211..aae5c33635 100644
--- a/test/behavior/eval.zig
+++ b/test/behavior/eval.zig
@@ -991,6 +991,16 @@ test "closure capture type of runtime-known parameter" {
     try S.b(c);
 }
 
+test "closure capture type of runtime-known var" {
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
+
+    var x: u32 = 1234;
+    const S = struct { val: @TypeOf(x + 100) };
+    const s: S = .{ .val = x };
+    try expect(s.val == 1234);
+}
+
 test "comptime break passing through runtime condition converted to runtime break" {
     if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;