qml: fix parser grammar for argument deconstruction

Previously, it was hardcoding a StringLiteralPropertyName for
a BindingIdentifier. This does not make sense because
BindingIdentifier cannot be string literals, they have to be
identifiers.

Also, this is problematic for deconstruction, e.g.:
```
function f(something) {
    let { x = 'x' } = something;  // (1)
    return x;
}
```
In (1), you cannot differentiate between the property
name x and the string literal x, because the parser creates a
string literal with value 'x' for both.
Notably, qmlls cannot differentiate between a 'find usages' on the
first x that is supposed to find the x in the return statement, and
the second "x" that is supposed to find no usages because it is a string
literal.

Same happens also for deconstruction in method parameters.

Add tests for qmlls for deconstruction in let-statements, and method
parameters. Make sure qmlformat ignores this qmlfile as it cannot
format deconstruction yet.

Task-number: QTBUG-100084
Change-Id: Ib7df974437e442dc0bfca75381c773c4d30b11bb
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/qml/parser/qqmljs.g b/src/qml/parser/qqmljs.g
index 902e8290b4..5b8c5d0eaa 100644
--- a/src/qml/parser/qqmljs.g
+++ b/src/qml/parser/qqmljs.g
@@ -3330,7 +3330,7 @@ BindingElisionElement: ElisionOpt BindingElement;
 BindingProperty: BindingIdentifier InitializerOpt_In;
 /.
     case $rule_number: {
-        AST::StringLiteralPropertyName *name = new (pool) AST::StringLiteralPropertyName(stringRef(1));
+        AST::IdentifierPropertyName *name = new (pool) AST::IdentifierPropertyName(stringRef(1));
         name->propertyNameToken = loc(1);
         // if initializer is an anonymous function expression, we need to assign identifierref as it's name
         if (auto *f = asAnonymousFunctionDefinition(sym(2).Expression))