Add C-/JS-APIs for lowMemoryUnused and pass arguments (#2639)

Allows a user to enable/disable the `lowMemoryUnused` option and to get/set/clear arbitrary pass arguments when using the C- or JS-APIs.

* binaryen.**getLowMemoryUnused**(): `boolean`
* binaryen.**setLowMemoryUnused**(on: `boolean`): `void`
* binaryen.**getPassArgument**(key: `string`): `string | null`
* binaryen.**setPassArgument**(key: `string`, value: `string | null`): `void`
* binaryen.**clearPassArguments**(): `void`

1 files changed, 25 insertions, 0 deletions

diff --git a/test/binaryen.js/pass-arguments.js.txt b/test/binaryen.js/pass-arguments.js.txt
new file mode 100644
index 000000000..f877b2248
--- /dev/null
+++ b/test/binaryen.js/pass-arguments.js.txt
@@ -0,0 +1,25 @@
+// beginning a Binaryen API trace
+#include <math.h>
+#include <map>
+#include "binaryen-c.h"
+int main() {
+  std::map<size_t, BinaryenExpressionRef> expressions;
+  std::map<size_t, BinaryenFunctionRef> functions;
+  std::map<size_t, BinaryenGlobalRef> globals;
+  std::map<size_t, BinaryenEventRef> events;
+  std::map<size_t, BinaryenExportRef> exports;
+  std::map<size_t, RelooperBlockRef> relooperBlocks;
+  BinaryenModuleRef the_module = NULL;
+  RelooperRef the_relooper = NULL;
+  BinaryenGetPassArgument("theKey");
+  BinaryenSetPassArgument("theKey", "theValue");
+  BinaryenGetPassArgument("theKey");
+  BinaryenSetPassArgument("theKey", NULL);
+  BinaryenGetPassArgument("theKey");
+  BinaryenSetPassArgument("theKey", "theValue2");
+  BinaryenGetPassArgument("theKey");
+  BinaryenClearPassArguments();
+  BinaryenGetPassArgument("theKey");
+  return 0;
+}
+// ending a Binaryen API trace