test: Prepare the test scripts for testing native Windows tools via WSL

Use the TOOLEXT variable in run-tests.sh in the same way as in the
Makefile. The Makefile sets this variable automatically if invoked
by mingw32-make, but if running run-tests.sh in WSL with native
Windows compilers, then we need to set TOOLEXT manually when calling
run-tests.sh.

Allow skipping the cfguard failure tests when run in such a
configuration, since Linux make in WSL can't easily run cmd.exe
like in MSYS2.

run-tests.sh

@@ -52,14 +52,14 @@ cat<<EOF > is-ucrt.c
 #endif
 EOF
 ANY_ARCH=$(echo $ARCHS | awk '{print $1}')
-if ! $ANY_ARCH-w64-mingw32-gcc -E is-ucrt.c > /dev/null 2>&1; then
+if ! $ANY_ARCH-w64-mingw32-gcc$TOOLEXT -E is-ucrt.c > /dev/null 2>&1; then
     # If the default CRT isn't UCRT, we can't build for mingw32uwp.
     unset HAVE_UWP
 fi
 rm -f is-ucrt.c
 
-if (echo "int main(){}" | $ANY_ARCH-w64-mingw32-clang -x c++ - -o has-cfguard-test.exe -mguard=cf); then
+if (echo "int main(){}" | $ANY_ARCH-w64-mingw32-clang$TOOLEXT -x c++ - -o has-cfguard-test.exe -mguard=cf); then
-    if llvm-readobj --coff-load-config has-cfguard-test.exe | grep -q 'CF_INSTRUMENTED (0x100)'; then
+    if llvm-readobj$TOOLEXT --coff-load-config has-cfguard-test.exe | grep -q 'CF_INSTRUMENTED (0x100)'; then
         HAVE_CFGUARD=1
     elif [ -n "$HAVE_CFGUARD" ]; then
         echo "error: Toolchain doesn't seem to include Control Flow Guard support." 1>&2

test/Makefile

@@ -252,8 +252,12 @@ ifeq ($(CMD),)
     FAILURE_TEST_TARGETS = $(addprefix .failtested., $(FAILURE_TESTS))
     CUSTOM1_FAILURE_TEST_TARGETS = .customtest1.bufferoverflow-fortify$(EXEEXT)
     ifneq ($(HAVE_CFGUARD),)
+    ifeq ($(WSL),)
+        # These tests do special calling of cmd.exe, which don't quite
+        # work when running with Linux make in WSL.
         CUSTOM2_FAILURE_TEST_TARGETS = .customtest2.cfguard-test$(EXEEXT)
     endif
+    endif
 endif
 endif