Cherry-pick d102e7a. rdar://problem/101940195

    Fix duplicated name in class static block
    https://bugs.webkit.org/show_bug.cgi?id=247426
    rdar://101940195

    Reviewed by Mark Lam.

    When parsing block statement in static block mode, we should alllow
    var declaration in the block scope. This is becuase static block is
    evaluated as a function call, where function scope should allow var
    declaration. In this case, var variables would be bounded under the
    static block scope when checking hoistable declarations in the parsing phase.

    * JSTests/stress/class-static-block.js:
    (foo.x):
    (foo):
    * Source/JavaScriptCore/parser/Parser.cpp:
    (JSC::Parser<LexerType>::parseBlockStatement):
    * Source/JavaScriptCore/parser/Parser.h:
    (JSC::Scope::setAllowsVarDeclarations):

    Canonical link: https://commits.webkit.org/256311@main

Canonical link: https://commits.webkit.org/256138.58@safari-7615.1.12-branch

JSTests/stress/class-static-block.js

@@ -647,3 +647,11 @@ shouldThrow(() => {
         }
     }
 }
+
+{
+    class x { 
+        static { 
+            var x; 
+        } 
+    }
+}

Source/JavaScriptCore/parser/Parser.cpp

@@ -1918,15 +1918,16 @@ template <class TreeBuilder> TreeStatement Parser<LexerType>::parseBlockStatemen
     if (shouldPushLexicalScope) {
         ScopeRef newScope = pushScope();
         newScope->setIsLexicalScope();
-        newScope->preventVarDeclarations();
         switch (type) {
         case BlockType::CatchBlock:
             newScope->setIsCatchBlockScope();
+            newScope->preventVarDeclarations();
             break;
         case BlockType::StaticBlock:
             newScope->setIsStaticBlock();
             break;
         case BlockType::Normal:
+            newScope->preventVarDeclarations();
             break;
         default:
             RELEASE_ASSERT_NOT_REACHED();