gcc emulation: Intellisense produces error where GCC does not in the case of statement expressions

Environment

• OS and Version: macOS Sequoia 15.5
• VS Code Version: 1.100.3
• C/C++ Extension Version: 1.25.3
• If using SSH remote, specify OS of remote machine: Ubuntu 20.04.6 LTS

Bug Summary and Steps to Reproduce

Bug Summary:
When given a minimal program which initializes a static instance of a class inside a GCC statement expression, Intellisense produces an error squiggle while the program compiles cleanly in GCC. This is using GCC 10.5.0 on Ubuntu 20.04 (x86_64).

Steps to reproduce:
Create a CMake project with a single C++ file with this content:

class ValueContainer
{
public:
    ValueContainer(int value) : value_(value) {}

private:
    int value_;
};

#define DO_SOMETHING(value) (({ \
    static ValueContainer foo{value}; \
    &foo; \
}))

int main()
{
    DO_SOMETHING(1);
    return 0;
}

Enable the VSCode C++ and CMake Tools extensions on the project.

An error squiggle is seen at line 17 with the message "a dynamically-initialized local static variable is not allowed inside of a statement expressionC/C++(1232)".

The program compiles cleanly with no warnings with GCC either invoked from the command line or via the CMake Tools extension.

Expected behavior:
VS Code produces no error squiggles

Configuration and Logs

C++ configured automatically through CMake Tools, the default configuration. Here is a dump from the debug logs:

Custom browse configuration received: {
  "browsePath": [
    "/home/skearney/devenv-wip/vscode-cpp-test"
  ],
  "compilerPath": "/usr/bin/X11/g++",
  "compilerArgs": [],
  "compilerFragments": [
    "-g"
  ]
}

Other Extensions

No response

Additional context

No response

Start by reproducing the minimal CMake project and comparing the IntelliSense squiggle with GCC's clean result. Trace how IntelliSense handles GCC statement expressions containing a dynamically initialized local static, then verify that the diagnostic disappears while valid diagnostics remain.