VLAs in C appear to not work on Windows, so use COMPILER_RT_ALLOCA:
C:\b\slave\sanitizer-windows\llvm-project\compiler-rt\lib\profile\InstrProfilingWriter.c(264): error C2057: expected constant expression
C:\b\slave\sanitizer-windows\llvm-project\compiler-rt\lib\profile\InstrProfilingWriter.c(264): error C2466: cannot allocate an array of constant size 0
C:\b\slave\sanitizer-windows\llvm-project\compiler-rt\lib\profile\InstrProfilingWriter.c(264): error C2133: 'Zeroes': unknown size
/* Enough zeroes for padding. */
unsigned PageSize = getpagesize();
- char Zeroes[PageSize];
+ char *Zeroes = (char *)COMPILER_RT_ALLOCA(PageSize);
memset(Zeroes, 0, PageSize);
/* Create the header. */