Fix "access violation" failures that have appeared in new windows builds by disabling compiler optimization on windows (#1077)

The root cause was a compiler autovectorization bug. Turning off
optimizations will hurt performance but at least make the code not
*totally broken*.

Reproduction of the bug in a simpler instance:

```
#include <cstdint>
#include <iostream>

uint64_t repro() {
    uint32_t targets[6]{0, 27, 0, 0, 27, 0};
    uint64_t t = 6;
    for (size_t k = 0; k < 6; k++) {
        if (targets[k] == 27) {
            t -= 2;
        }
    }
    return t;
}

int main() {
    std::cerr << "t=" << repro() << "\n";
    return 0;
}
```

Go to godbolt, paste the above code, compile it with the compiler `x64
msvc v19.51 VS18.6` and flags `/O2` and run it and it will print
`t=8589934594` instead of `t=2`.

Fixes #1078

Author: Strilanc

pyproject.toml

@@ -1,3 +1,9 @@
 [build-system]
 requires = ["setuptools", "wheel", "pybind11~=2.11.1"]
 build-backend = "setuptools.build_meta"
+
+[tool.cibuildwheel.windows.environment]
+# CAUTION! This is /Od instead of /O2 because of bugs in the msvc compiler!
+# See: https://github.com/quantumlib/Stim/issues/1078
+CFLAGS = "/Od"
+CXXFLAGS = "/Od"

setup.py

@@ -30,7 +30,9 @@
 if platform.system().startswith('Win'):
     common_compile_args = [
         '/std:c++20',
-        '/O2',
+        # CAUTION! This is /Od instead of /O2 because of bugs in the msvc compiler!
+        # See: https://github.com/quantumlib/Stim/issues/1078
+        '/Od',
         f'/DVERSION_INFO={__version__}',
     ]
     arch_avx = ['/arch:AVX2']