mbstring cannot be built on Windows (commit f7e7370)

[vpalm001]

Description

PHP 8.3.5 (to be released) cannot be built on Windows (vs16).
msvc does not allow (optional std c11) variable length arrays.
Breaking commit: f7e7370

Error message:

ext\mbstring\mbstring.c(5887): error C2057: expected constant expression
ext\mbstring\mbstring.c(5887): error C2466: cannot allocate an array of constant size 0
ext\mbstring\mbstring.c(5887): error C2133: 'wchar_buf': unknown size
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\VC\Tools\MSVC\14.28.29910\bin\HostX64\x64\cl.exe"' : return code '0x2'

PHP Version

PHP 8.3.5

Operating System

Windows