github: Run tests directly after cross compiling the msvcrt runtimes

This matches what is done for the regular builds; we run (build-only)
tests already with the first cross compiler toolchains, not needing
to wait for the cross compiled toolchains to run on Windows.

.github/workflows/msvcrt.yml

@@ -124,6 +124,8 @@ jobs:
           sudo apt-get update && sudo apt-get install libltdl-dev swig autoconf-archive
           ./build-cross-tools.sh /opt/llvm-mingw $(pwd)/install/llvm-mingw ${{matrix.arch}} --with-python --thinlto --pgo
           .github/workflows/store-version.sh install/llvm-mingw/versions.txt
+          ./test-libcxx-module.sh $(pwd)/install/llvm-mingw
+          ./run-tests.sh $(pwd)/install/llvm-mingw
           cd install
           NAME=llvm-mingw-$TAG-${{matrix.crt}}-${{matrix.arch}}
           mv llvm-mingw $NAME