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

[aoikonomopoulos]

LGTM, as long as the test262 tests pass.