Update appveyor build to use latest MinGW

[mikee47]

Let's have another try to get appveyor working again.
For reference, appveyor builds on my account are without issue.

[mikee47]

No effect. Closing as #2086 is still open.

[slaff]

Appveyor is really bugging me. We should try Travis Windows builds

[mikee47]

@slaff On the plus (!) side, as of yesterday I'm working with this latest version of MinGW (which has GCC 9.2 vs 8.2) and.. guess what:

CC /s/sandboxes/sming-tmp/Sming/Components/bearssl-esp8266/bearssl/src/x509/skey_decoder.c
CC /s/sandboxes/sming-tmp/Sming/Components/bearssl-esp8266/bearssl/src/x509/x509_decoder.c
CC /s/sandboxes/sming-tmp/Sming/Components/bearssl-esp8266/bearssl/src/x509/x509_knownkey.c
CC /s/sandboxes/sming-tmp/Sming/Components/bearssl-esp8266/bearssl/src/x509/x509_minimal.c
CC /s/sandboxes/sming-tmp/Sming/Components/bearssl-esp8266/bearssl/src/x509/x509_minimal_full.c
AR /s/sandboxes/sming-tmp/Sming/out/Host/debug/lib/clib-bearssl-esp8266.a
C:\MinGW\msys\1.0\bin\make.exe: *** couldn't commit memory for cygwin heap, Win32 error 0
make: *** [bearssl-esp8266-build] Error 1

So finally, I can reproduce the error on my dev. machine. I've got 32GB RAM so it's not that :-)

[slaff]

So finally, I can reproduce the error on my dev. machine.

Try to find the culprit but don't investigate too much time on this.

[mikee47]

@slaff Are you looking into Windows on Travis or shall I have a pop?

[mikee47]

@slaff Scratch my question I see you're cracking on :-)

[slaff]

Are you looking into Windows on Travis or shall I have a pop?

But my progress is sooo slow that I have nothing against you trying Windows on Travis.

[mikee47]

I'm working on other stuff but if you get bored happy to pick at it...

[mikee47]

@slaff Made some (slow) progress with travis builds - https://travis-ci.org/github/mikee47/Sming/builds/738497211

Strangely, it's failed running some crypto tests - investigating - but progress!