Implement support for class static initialization blocks …

[vdinak240]

https://bugswebkit.org/show_bug.cgi?id=235085 rdar://99056882

Reviewed by Yusuke Suzuki.

Class static initialization block is a new feature of a class to perform additional static initialization during class definition evaluation.

class C {
    static { /* … */ }
}

TC39 Spec: https://tc39.es/proposal-class-static-block/
TC39 Proposal: https://github.com/tc39/proposal-class-static-block
MDN Web Doc: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Class_static_initialization_blocks

In this patch, static blocks are implemented as functions which are evaluated along with the initialization of static class fields during class definition evaluation. This can be further optimized by inlining static block functions to the field initialization.

• JSTests/stress/class-static-block.js: Added. (assert):
  (A):
  (assert.C):
  (assert.B):
  (assert.D):
  (assert.A):
  (assert.A.friendA.prototype.getX):
  (assert.A.friendA.prototype.setX):
  (assert.A.prototype.getX):
  (assert.inner):
  (catch.C.prototype.async inner):
  (catch.C):
  (catch):
  (async inner.C.prototype.async inner):
  (async inner.C):
  (async inner):
  (C.inner):
  (C):
  (await.C.inner):
  (await.C):
  (await):
  (arguments.C.inner):
  (arguments.C):
  (arguments):
• Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp: (JSC::PropertyListNode::emitBytecode):
  (JSC::FunctionCallValueNode::emitBytecode):
  (JSC::FuncExprNode::emitBytecode):
• Source/JavaScriptCore/parser/ASTBuilder.h: (JSC::ASTBuilder::createFunctionExpr):
  (JSC::ASTBuilder::createProperty):
  (JSC::ASTBuilder::makeFunctionCallNode):
• Source/JavaScriptCore/parser/NodeConstructors.h: (JSC::PropertyNode::PropertyNode):
  (JSC::FunctionCallValueNode::FunctionCallValueNode): (JSC::FuncExprNode::FuncExprNode):
• Source/JavaScriptCore/parser/Nodes.h: (JSC::FuncExprNode::isStaticBlockFunction const):
• Source/JavaScriptCore/parser/Parser.cpp: (JSC::Parser::isArrowFunctionParameters): (JSC::Parser::parseStatementListItem):
  (JSC::Parser::parseVariableDeclarationList): (JSC::Parser::parseBreakStatement):
  (JSC::Parser::parseContinueStatement):
  (JSC::Parser::parseReturnStatement):
  (JSC::Parser::parseTryStatement):
  (JSC::Parser::parseBlockStatement):
  (JSC::stringArticleForFunctionMode):
  (JSC::stringForFunctionMode):
  (JSC::Parser::parseFunctionParameters): (JSC::Parser::parseFunctionInfo):
  (JSC::Parser::parseClass):
  (JSC::Parser::parseClassFieldInitializerSourceElements): (JSC::Parser::parseAssignmentExpression): (JSC::Parser::parsePrimaryExpression):
  (JSC::Parser::parseMemberExpression):
  (JSC::Parser::parseUnaryExpression):
• Source/JavaScriptCore/parser/Parser.h: (JSC::Scope::setSourceParseMode):
  (JSC::Scope::setIsStaticBlockScope):
  (JSC::Scope::isStaticBlockScope):
  (JSC::Parser::canUseIdentifierAwait):
  (JSC::Parser::disallowedIdentifierAwaitReason):
  (JSC::Parser::findClosetFunctionScope):
  (JSC::Parser::findClosetAsyncFunctionScope):
  (JSC::Parser::findScopeUntilStaticBlock):
• Source/JavaScriptCore/parser/ParserModes.h: (JSC::isFunctionParseMode):
  (JSC::isMethodParseMode):
• Source/JavaScriptCore/parser/SyntaxChecker.h: (JSC::SyntaxChecker::makeFunctionCallNode):
  (JSC::SyntaxChecker::createFunctionExpr):
  (JSC::SyntaxChecker::createProperty):
• Source/JavaScriptCore/runtime/FunctionExecutable.cpp: (JSC::FunctionExecutable::toStringSlow):

Canonical link: https://commits.webkit.org/255173@main
5cc281d

Build-Tests	Layout-Tests
✅ 🛠 wpe-238-amd64-build	✅ 🧪 wpe-238-amd64-layout
✅ 🛠 wpe-238-arm32-build	✅ 🧪 wpe-238-arm32-layout

[aoikonomopoulos]

LGTM, as long as the test262 tests pass.

[pgorszkowski-igalia]

Before I merge it I have to run test262.

[pgorszkowski-igalia]

The test262 results without this change:

[47110/47190]
80943 tests run
4826 test files skipped
1307 tests failed in total
2 tests newly fail
60 tests newly pass

and the test262 results with this change:

[47110/47190]
80943 tests run
4826 test files skipped
1307 tests failed in total
2 tests newly fail
60 tests newly pass

Both are the same. No regressions.

I built(Tools/Scripts/build-webkit --jsc-only) and run(Tools/Scripts/test262-runner --release --jsc ./WebKitBuild/Release/bin/jsc) wpe-2.38 on armv8l.

@aoikonomopoulos : so I will merge it.