regres: Don't ignore abnormal exits

Bug: b/144426261
Change-Id: Ic515f274bf1c02afbbe3f536c1c8cd654b0cc56e
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/38168
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Chris Forbes <chrisforbes@google.com>
diff --git a/tests/regres/main.go b/tests/regres/main.go
index ca0ae09..f57e305 100644
--- a/tests/regres/main.go
+++ b/tests/regres/main.go
@@ -1337,8 +1337,10 @@
 		// Don't treat non-zero error codes as crashes.
 		var exitErr *exec.ExitError
 		if errors.As(err, &exitErr) {
-			out += fmt.Sprintf("\nProcess terminated with code %d", exitErr.ExitCode())
-			err = nil
+			if exitErr.ExitCode() != -1 {
+				out += fmt.Sprintf("\nProcess terminated with code %d", exitErr.ExitCode())
+				err = nil
+			}
 		}
 
 		switch err.(type) {