ports: Make new ports/ sub-directory and move all ports there.

This is to keep the top-level directory clean, to make it clear what is
core and what is a port, and to allow the repository to grow with new ports
in a sustainable way.

ports/qemu-arm/test_main.c

@@ -0,0 +1,94 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <malloc.h>
+
+#include "py/nlr.h"
+#include "py/obj.h"
+#include "py/compile.h"
+#include "py/runtime0.h"
+#include "py/runtime.h"
+#include "py/stackctrl.h"
+#include "py/gc.h"
+#include "py/mperrno.h"
+
+#include "tinytest.h"
+#include "tinytest_macros.h"
+
+#define HEAP_SIZE (128 * 1024)
+STATIC void *heap;
+
+void do_str(const char *src);
+inline void do_str(const char *src) {
+    gc_init(heap, (char*)heap + HEAP_SIZE);
+    mp_init();
+
+    nlr_buf_t nlr;
+    if (nlr_push(&nlr) == 0) {
+        mp_lexer_t *lex = mp_lexer_new_from_str_len(MP_QSTR__lt_stdin_gt_, src, strlen(src), 0);
+        qstr source_name = lex->source_name;
+        mp_parse_tree_t parse_tree = mp_parse(lex, MP_PARSE_FILE_INPUT);
+        mp_obj_t module_fun = mp_compile(&parse_tree, source_name, MP_EMIT_OPT_NONE, false);
+        mp_call_function_0(module_fun);
+        nlr_pop();
+    } else {
+        mp_obj_t exc = (mp_obj_t)nlr.ret_val;
+        if (mp_obj_is_subclass_fast(mp_obj_get_type(exc), &mp_type_SystemExit)) {
+            // Assume that sys.exit() is called to skip the test.
+            // TODO: That can be always true, we should set up convention to
+            // use specific exit code as skip indicator.
+            tinytest_set_test_skipped_();
+            goto end;
+        }
+        mp_obj_print_exception(&mp_plat_print, exc);
+        tt_abort_msg("Uncaught exception");
+    }
+end:
+    mp_deinit();
+}
+
+#include "genhdr/tests.h"
+
+int main() {
+    const char a[] = {"sim"};
+    mp_stack_ctrl_init();
+    mp_stack_set_limit(10240);
+    heap = malloc(HEAP_SIZE);
+    int r = tinytest_main(1, (const char **) a, groups);
+    printf( "status: %i\n", r);
+    return r;
+}
+
+void gc_collect(void) {
+    gc_collect_start();
+
+    // get the registers and the sp
+    jmp_buf env;
+    setjmp(env);
+    volatile mp_uint_t dummy;
+    void *sp = (void*)&dummy;
+
+    // trace the stack, including the registers (since they live on the stack in this function)
+    gc_collect_root((void**)sp, ((uint32_t)MP_STATE_THREAD(stack_top) - (uint32_t)sp) / sizeof(uint32_t));
+
+    gc_collect_end();
+}
+
+mp_lexer_t *mp_lexer_new_from_file(const char *filename) {
+    mp_raise_OSError(MP_ENOENT);
+}
+
+mp_import_stat_t mp_import_stat(const char *path) {
+    return MP_IMPORT_STAT_NO_EXIST;
+}
+
+mp_obj_t mp_builtin_open(size_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_open_obj, 1, mp_builtin_open);
+
+void nlr_jump_fail(void *val) {
+    printf("uncaught NLR\n");
+    exit(1);
+}