Add API for accessing command-line arguments.

- Add process module with Process class.
- Add "arguments" and "allArguments" methods.
- Docs for same.
- Support passing additional arguments to command line.
- Add "--help" support to command line.

src/cli/main.c

@@ -1,22 +1,26 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "process.h"
 #include "vm.h"
 #include "wren.h"
 
 int main(int argc, const char* argv[])
 {
-  if (argc < 1 || argc > 2)
+  if (argc == 2 && strcmp(argv[1], "--help") == 0)
   {
-    fprintf(stderr, "Usage: wren [file]\n");
-    return 64; // EX_USAGE.
+    printf("Usage: wren [file] [arguments...]\n");
+    printf("  --help  Show command line usage\n");
+    return 0;
   }
+  
+  processSetArguments(argc, argv);
 
   if (argc == 1)
   {
     runRepl();
   }
-  else if (argc == 2)
+  else
   {
     runFile(argv[1]);
   }

src/cli/modules.c

@@ -4,6 +4,7 @@
 #include "modules.h"
 
 #include "io.wren.inc"
+#include "process.wren.inc"
 #include "scheduler.wren.inc"
 #include "timer.wren.inc"
 
@@ -17,6 +18,7 @@ extern void fileClose(WrenVM* vm);
 extern void fileDescriptor(WrenVM* vm);
 extern void fileReadBytes(WrenVM* vm);
 extern void fileSize(WrenVM* vm);
+extern void processAllArguments(WrenVM* vm);
 extern void stdinReadStart(WrenVM* vm);
 extern void stdinReadStop(WrenVM* vm);
 extern void schedulerCaptureMethods(WrenVM* vm);
@@ -109,6 +111,11 @@ static ModuleRegistry modules[] =
       STATIC_METHOD("readStop_()", stdinReadStop)
     END_CLASS
   END_MODULE
+  MODULE(process)
+    CLASS(Process)
+      STATIC_METHOD("allArguments", processAllArguments)
+    END_CLASS
+  END_MODULE
   MODULE(scheduler)
     CLASS(Scheduler)
       STATIC_METHOD("captureMethods_()", schedulerCaptureMethods)