mingw: Fix number of exponent digits in floating point formatting

By default mingw outputs 3 digits instead of the standard 2 so all float
tests using printf fail. Using setenv at the start of the program fixes this.
To accomodate calling platform specific initialization a
MICROPY_MAIN_INIT_FUNC macro is used which is called in mp_init()

1 files changed, 1 insertions, 0 deletions

diff --git a/windows/init.h b/windows/init.h
new file mode 100644
index 000000000..d081a2052
--- /dev/null
+++ b/windows/init.h
@@ -0,0 +1 @@
+void init();