LibJS: Propogate allocation errors in BigInt constructor functions

Author: https://github.com/ttrssreal
Commit: 8ed7dee0f0
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3615

Libraries/LibJS/Runtime/BigIntConstructor.cpp

@@ -75,7 +75,7 @@ JS_DEFINE_NATIVE_FUNCTION(BigIntConstructor::as_int_n)
     // 3. Let mod be ℝ(bigint) modulo 2^bits.
     // FIXME: For large values of `bits`, this can likely be improved with a SignedBigInteger API to
     //        drop the most significant bits.
-    auto bits_shift_left = BIGINT_ONE.shift_left(bits);
+    auto bits_shift_left = TRY_OR_THROW_OOM(vm, BIGINT_ONE.try_shift_left(bits));
     auto mod = modulo(bigint->big_integer(), bits_shift_left);
 
     // 4. If mod ≥ 2^(bits-1), return ℤ(mod - 2^bits); otherwise, return ℤ(mod).
@@ -101,7 +101,7 @@ JS_DEFINE_NATIVE_FUNCTION(BigIntConstructor::as_uint_n)
     // 3. Return the BigInt value that represents ℝ(bigint) modulo 2bits.
     // FIXME: For large values of `bits`, this can likely be improved with a SignedBigInteger API to
     //        drop the most significant bits.
-    return BigInt::create(vm, modulo(bigint->big_integer(), BIGINT_ONE.shift_left(bits)));
+    return BigInt::create(vm, modulo(bigint->big_integer(), TRY_OR_THROW_OOM(vm, BIGINT_ONE.try_shift_left(bits))));
 }
 
 }

Libraries/LibJS/Tests/builtins/BigInt/BigInt.asIntN.js

@@ -22,6 +22,12 @@ describe("errors", () => {
             BigInt.asIntN(1, "foo");
         }).toThrowWithMessage(SyntaxError, "Invalid value for BigInt: foo");
     });
+
+    test("large allocation", () => {
+        expect(() => {
+            BigInt.asIntN(0x4000000000000, 1n);
+        }).toThrowWithMessage(InternalError, "Out of memory");
+    });
 });
 
 describe("correct behavior", () => {

Libraries/LibJS/Tests/builtins/BigInt/BigInt.asUintN.js

@@ -22,6 +22,12 @@ describe("errors", () => {
             BigInt.asUintN(1, "foo");
         }).toThrowWithMessage(SyntaxError, "Invalid value for BigInt: foo");
     });
+
+    test("large allocation", () => {
+        expect(() => {
+            BigInt.asUintN(0x4000000000000, 1n);
+        }).toThrowWithMessage(InternalError, "Out of memory");
+    });
 });
 
 describe("correct behavior", () => {