Revert "llvm: fix lowering pointer to final zero-width field of a comptime value"

This reverts commit e0bc5f65b98d154b4318027d56f780b55605e33c.

Caused an assertion failure when running the behavior tests:

```
zig: llvm/lib/IR/Type.cpp:729: static llvm::PointerType* llvm::PointerType::get(llvm::Type*, unsigned int): Assertion `isValidElementType(EltTy) && "Invalid type for pointer element!"' failed.
Aborted (core dumped)
```

1 files changed, 13 insertions, 23 deletions

diff --git a/test/behavior/struct.zig b/test/behavior/struct.zig
index 0984f7d1e4..db7092ab82 100644
--- a/test/behavior/struct.zig
+++ b/test/behavior/struct.zig
@@ -1359,33 +1359,23 @@ test "under-aligned struct field" {
     try expect(result == 1234);
 }
 
-test "fieldParentPtr of a zero-bit field" {
+test "address of zero-bit field is equal to address of only field" {
     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 S = struct {
-        fn testOneType(comptime A: type) !void {
-            {
-                const a = A{ .u = 0 };
-                const b_ptr = &a.b;
-                const a_ptr = @fieldParentPtr(A, "b", b_ptr);
-                try std.testing.expectEqual(&a, a_ptr);
-            }
-            {
-                var a = A{ .u = 0 };
-                const b_ptr = &a.b;
-                const a_ptr = @fieldParentPtr(A, "b", b_ptr);
-                try std.testing.expectEqual(&a, a_ptr);
-            }
-        }
-        fn doTheTest() !void {
-            try testOneType(struct { b: void = {}, u: u8 });
-            try testOneType(struct { u: u8, b: void = {} });
-        }
-    };
-    try S.doTheTest();
-    comptime try S.doTheTest();
+    {
+        const A = struct { b: void = {}, u: u8 };
+        var a = A{ .u = 0 };
+        const a_ptr = @fieldParentPtr(A, "b", &a.b);
+        try std.testing.expectEqual(&a, a_ptr);
+    }
+    {
+        const A = struct { u: u8, b: void = {} };
+        var a = A{ .u = 0 };
+        const a_ptr = @fieldParentPtr(A, "b", &a.b);
+        try std.testing.expectEqual(&a, a_ptr);
+    }
 }
 
 test "struct field has a pointer to an aligned version of itself" {