Preserve temp directory when running isolated test on Windows

Author: pbo-linaro

pkgs/native_assets_builder/lib/src/utils/run_process.dart

@@ -28,6 +28,8 @@ Future<RunProcessResult> runProcess({
   if (Platform.isWindows && !includeParentEnvironment) {
     const winEnvKeys = [
       'SYSTEMROOT',
+      'TEMP',
+      'TMP',
     ];
     environment = {
       for (final winEnvKey in winEnvKeys)

pkgs/native_toolchain_c/lib/src/utils/run_process.dart

@@ -27,6 +27,8 @@ Future<RunProcessResult> runProcess({
   if (Platform.isWindows && !includeParentEnvironment) {
     const winEnvKeys = [
       'SYSTEMROOT',
+      'TEMP',
+      'TMP',
     ];
     environment = {
       for (final winEnvKey in winEnvKeys)