Fix lastcontinuehandler when built as library

When a golang package is built as a c-shared or c-archive for being
loaded in a non-go program, it should not crash the program when an
exception is observed, but let the main program runtime decide what to
do.

This fixes this behavior for c-shared/c-archive on Windows

Signed-off-by: Simon Ferquel <[email protected]>

Author: simonferquel

src/runtime/signal_windows.go

@@ -171,6 +171,13 @@ var testingWER bool
 //
 //go:nosplit
 func lastcontinuehandler(info *exceptionrecord, r *context, gp *g) int32 {
+	if (islibrary || isarchive) &&
+		!isgoexception(info, r) {
+		// go has been loaded in a non-go program.
+		// if the exception does not originate from go, the go runtime
+		// should not take responsibility of crashing the process
+		return _EXCEPTION_CONTINUE_SEARCH
+	}
 	if testingWER {
 		return _EXCEPTION_CONTINUE_SEARCH
 	}