[TurboFan] Add BigInt support to %VerifyType

This CL adds handling of the BigInt types to TurbofanType to allow
verification of BigInt values in %VerifyType.

Change-Id: I1fc6dea16cbff4d22cfbb5483c5dee50fa932f75
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3256687Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79169}

src/objects/turbofan-types.tq

@@ -4,6 +4,11 @@
 
 #include "src/objects/turbofan-types.h"
 
+const kMaxIntPtr: constexpr IntegerLiteral
+    generates 'IntegerLiteral(ca_.Is64() ? 0x7FFFFFFFFFFFFFFF : 0x7FFFFFFF)';
+const kMinIntPtr: constexpr IntegerLiteral
+    generates 'IntegerLiteral(ca_.Is64() ? 0x8000000000000000 : 0x80000000)';
+
 @export
 @abstract
 class TurbofanType extends HeapObject {
@@ -154,11 +159,37 @@ macro TestTurbofanBitsetType(
     case (JSArray): {
       return bitsetLow.array;
     }
-    case (BigInt): {
-      // TODO (tebbi): Distinguish different BigInt types.
-      return bitsetLow.unsigned_big_int_63 |
-          bitsetLow.other_unsigned_big_int_64 | bitsetLow.negative_big_int_63 |
-          bitsetLow.other_big_int;
+    case (bi: BigInt): {
+      dcheck(!bitsetLow.other_big_int || bitsetLow.other_unsigned_big_int_64);
+      dcheck(!bitsetLow.other_big_int || bitsetLow.negative_big_int_63);
+      dcheck(
+          !bitsetLow.other_unsigned_big_int_64 ||
+          bitsetLow.unsigned_big_int_63);
+      dcheck(!bitsetLow.negative_big_int_63 || bitsetLow.unsigned_big_int_63);
+
+      // On 32 bit architectures, [Un]signedBigInt64 types are not used, yet.
+      if (!Is64()) {
+        return bitsetLow.other_big_int;
+      }
+
+      const length = bigint::ReadBigIntLength(bi);
+      if (length > 1) {
+        return bitsetLow.other_big_int;
+      } else if (length == 0) {
+        return bitsetLow.unsigned_big_int_63;
+      }
+      dcheck(length == 1);
+      const sign = bigint::ReadBigIntSign(bi);
+      const digit = bigint::LoadBigIntDigit(bi, 0);
+      if (sign == bigint::kPositiveSign) {
+        return bitsetLow.other_unsigned_big_int_64 ||
+            (digit <= Convert<uintptr>(kMaxIntPtr) &&
+             bitsetLow.unsigned_big_int_63);
+      } else {
+        return bitsetLow.other_big_int ||
+            (digit <= Convert<uintptr>(kMinIntPtr) &&
+             bitsetLow.negative_big_int_63);
+      }
     }
     case (object: JSObject): {
       if (object.map.IsUndetectable()) {