Add resizable ArrayBuffers (#646)

This commit implements resizable ArrayBuffers - RABs for short - and
extends typed arrays (TAs) to support fixed-length and length-tracking
modes.

SharedArrayBuffers (SABs) also support the maxByteLength option now but
I cheated and allocate all memory upfront because atomically resizing
memory allocations is hard and this commit is already big and complex.

The lion's share is updating all the TA prototype methods to deal with
RABs resizing underneath them. Method arguments can be arbitrary objects
with arbitrary .valueOf methods and arbitrary side effects, like...
resizing the RAB we're currently operating on.

Fixes: https://github.com/quickjs-ng/quickjs/issues/477

quickjs-atom.h

@@ -176,6 +176,7 @@ DEF(not_equal, "not-equal")
 DEF(timed_out, "timed-out")
 DEF(ok, "ok")
 DEF(toJSON, "toJSON")
+DEF(maxByteLength, "maxByteLength")
 /* class names */
 DEF(Object, "Object")
 DEF(Array, "Array")

test262.conf

@@ -173,7 +173,7 @@ regexp-named-groups
 regexp-unicode-property-escapes
 regexp-v-flag
 RegExp.escape=skip
-resizable-arraybuffer=skip
+resizable-arraybuffer
 rest-parameters
 Set
 set-methods

test262_errors.txt

@@ -389,4 +389,7 @@ test262/test/language/expressions/assignment/target-super-computed-reference.js:
 test262/test/language/expressions/in/private-field-invalid-assignment-target.js:23: unexpected error type: Test262: This statement should not be evaluated.
 test262/test/language/expressions/in/private-field-invalid-assignment-target.js:23: strict mode: unexpected error type: Test262: This statement should not be evaluated.
 test262/test/language/module-code/top-level-await/async-module-does-not-block-sibling-modules.js:13: SyntaxError: Could not find export 'check' in module 'test262/test/language/module-code/top-level-await/async-module-sync_FIXTURE.js'
+test262/test/staging/ArrayBuffer/resizable/object-define-property-define-properties.js:55: strict mode: unexpected error: Test262Error: Expected a TypeError to be thrown but no exception was thrown at all
+test262/test/staging/ArrayBuffer/resizable/object-define-property-parameter-conversion-grows.js:67: strict mode: unexpected error: TypeError: out-of-bound index in typed array
+test262/test/staging/ArrayBuffer/resizable/object-define-property-parameter-conversion-shrinks.js:59: strict mode: unexpected error: Test262Error: Expected a TypeError to be thrown but no exception was thrown at all
 test262/test/staging/top-level-await/tla-hang-entry.js:10: TypeError: $DONE() not called

tests/test_bjson.js

@@ -139,6 +139,41 @@ function bjson_test(a)
     }
 }
 
+function bjson_test_arraybuffer()
+{
+    var buf, array_buffer;
+
+    array_buffer = new ArrayBuffer(4);
+    assert(array_buffer.byteLength, 4);
+    assert(array_buffer.maxByteLength, 4);
+    assert(array_buffer.resizable, false);
+    buf = bjson.write(array_buffer);
+    array_buffer = bjson.read(buf, 0, buf.byteLength);
+    assert(array_buffer.byteLength, 4);
+    assert(array_buffer.maxByteLength, 4);
+    assert(array_buffer.resizable, false);
+
+    array_buffer = new ArrayBuffer(4, {maxByteLength: 4});
+    assert(array_buffer.byteLength, 4);
+    assert(array_buffer.maxByteLength, 4);
+    assert(array_buffer.resizable, true);
+    buf = bjson.write(array_buffer);
+    array_buffer = bjson.read(buf, 0, buf.byteLength);
+    assert(array_buffer.byteLength, 4);
+    assert(array_buffer.maxByteLength, 4);
+    assert(array_buffer.resizable, true);
+
+    array_buffer = new ArrayBuffer(4, {maxByteLength: 8});
+    assert(array_buffer.byteLength, 4);
+    assert(array_buffer.maxByteLength, 8);
+    assert(array_buffer.resizable, true);
+    buf = bjson.write(array_buffer);
+    array_buffer = bjson.read(buf, 0, buf.byteLength);
+    assert(array_buffer.byteLength, 4);
+    assert(array_buffer.maxByteLength, 8);
+    assert(array_buffer.resizable, true);
+}
+
 /* test multiple references to an object including circular
    references */
 function bjson_test_reference()
@@ -292,6 +327,7 @@ function bjson_test_all()
         assert(e instanceof TypeError);
     }
 
+    bjson_test_arraybuffer();
     bjson_test_reference();
     bjson_test_regexp();
     bjson_test_map();