IntelliSense internal error 1504 on malformed enum constructor declaration #14817

c_cpp_properties.json:
{
    "configurations": [
        {
            "name": "Mac",
            "includePath": [
                "${workspaceFolder}/**"
            ],
            "defines": [],
            "cStandard": "c17",
            "intelliSenseMode": "macos-clang-arm64"
        }
    ],
    "version": 4
}
Diagnostics:
-------- Diagnostics - 10/4/2026, 7:14:27 PM
Version: 1.34.4
Current Configuration:
{
    "name": "Mac",
    "includePath": [
        "/var/folders/_r/b4g_tw1j3tq6b46wzlwc_8h00000gn/T/cpptools-repro-2d1rjnrn/workspace/**"
    ],
    "defines": [],
    "cStandard": "c17",
    "intelliSenseMode": "macos-clang-arm64",
    "compilerPathIsExplicit": true,
    "cStandardIsExplicit": true,
    "cppStandardIsExplicit": true,
    "intelliSenseModeIsExplicit": true,
    "recursiveIncludesPriorityIsExplicit": false,
    "recursiveIncludesOrderIsExplicit": false,
    "cppStandard": "c++20",
    "mergeConfigurations": false,
    "recursiveIncludes": {},
    "compilerPath": "/opt/homebrew/opt/llvm/bin/clang++",
    "browse": {
        "limitSymbolsToIncludedHeaders": true
    }
}
Modified Settings:
{
    "C_Cpp.default.compilerPath": "/opt/homebrew/opt/llvm/bin/clang++",
    "C_Cpp.default.cppStandard": "c++20",
    "C_Cpp.loggingLevel": "Debug"
}
Additional Tracked Settings:
{
    "editorTabSize": 4,
    "editorInsertSpaces": true,
    "editorAutoClosingBrackets": "languageDefined",
    "filesEncoding": "utf8",
    "filesAssociations": {},
    "filesExclude": {
        "**/.git": true,
        "**/.svn": true,
        "**/.hg": true,
        "**/.DS_Store": true,
        "**/Thumbs.db": true
    },
    "filesAutoSaveAfterDelay": false,
    "editorInlayHintsEnabled": true,
    "editorParameterHintsEnabled": true,
    "searchExclude": {
        "**/node_modules": true,
        "**/bower_components": true,
        "**/*.code-search": true
    },
    "workbenchSettingsEditor": "ui"
}
cpptools version (native): 1.34.3.0
Current database path: /Users/elliotmiller/Library/Caches/vscode-cpptools/510a4a88be99a8a17a93e2b81192563e/.browse.VC.db
Translation Unit Mappings:
[ /var/folders/_r/b4g_tw1j3tq6b46wzlwc_8h00000gn/T/cpptools-repro-2d1rjnrn/workspace/repro.cpp - source TU]:
Translation Unit Configurations:
[ /var/folders/_r/b4g_tw1j3tq6b46wzlwc_8h00000gn/T/cpptools-repro-2d1rjnrn/workspace/repro.cpp ]
    Process ID: 51480
    Memory Usage: 100 MB
    Compiler Path: /opt/homebrew/opt/llvm/bin/clang++
    Language: C++
    Include Paths:
        system include: /opt/homebrew/Cellar/llvm/23.1.0/include/c++/v1
        system include: /opt/homebrew/Cellar/llvm/23.1.0/lib/clang/23/include
        system include: /Library/Developer/CommandLineTools/SDKs/MacOSX26.sdk/usr/include
        system framework search path (default): /Library/Developer/CommandLineTools/SDKs/MacOSX26.sdk/System/Library/Frameworks
        system framework search path (default): /Library/Developer/CommandLineTools/SDKs/MacOSX26.sdk/System/Library/SubFrameworks
        include (recursive): /var/folders/_r/b4g_tw1j3tq6b46wzlwc_8h00000gn/T/cpptools-repro-2d1rjnrn/workspace
    Standard Version: c++20
    IntelliSense Mode: macos-clang-arm64
    Other Flags:
        --clang
        --clang_version=230100
Total Memory Usage: 100 MB