Author Name: Sergey Kvachonok (@ravenexp)
Original Redmine Issue: 1413 from https://www.veripool.org

Original Assignee: Sergey Kvachonok (@ravenexp)

Modern MinGW C runtime versions (starting from GCC 6)
have switched to C99/C++11 compliant printf/scanf
format specifiers when include is used.

OTOH, when <stdio.h> include is used, MinGW still
defaults to MS formats, but even then it can be
overridden with

#define __USE_MINGW_ANSI_STDIO 1

Source: https://sourceforge.net/p/mingw-w64/wiki2/printf%20and%20scanf%20family/

For GCC 5 MinGW and older, behaved just like <stdio.h>.

verilatedos.h header still assumes that MinGW always uses MS formats,
which breaks printing of 64-bit numbers on 32-bit MinGW GCC 6, 7 and 8.
Compiling verilated.cpp also prints an array of printf format warnings
with modern MinGW compilers for the 32-bit Windows target.

I've attached a patch which makes both old and new MinGW compilers
use the standard printf formats.
Older MinGW versions are just forced to use C99 formats with
the above preprocessor definition.