esp8266: Remove scanning of GC pointers in native code block.

The native code no longer holds live GC pointers so doesn't need to be
scanned.

ports/esp8266/gccollect.c

@@ -46,11 +46,6 @@ void gc_collect(void) {
     // trace the stack, including the registers (since they live on the stack in this function)
     gc_collect_root((void**)sp, (STACK_END - sp) / sizeof(uint32_t));
 
-    #if MICROPY_EMIT_XTENSA || MICROPY_EMIT_INLINE_XTENSA
-    // trace any native code because it can contain pointers to the heap
-    esp_native_code_gc_collect();
-    #endif
-
     // end the GC
     gc_collect_end();
 }

ports/esp8266/gccollect.h

@@ -40,6 +40,5 @@ extern uint32_t _heap_start;
 extern uint32_t _heap_end;
 
 void gc_collect(void);
-void esp_native_code_gc_collect(void);
 
 #endif // MICROPY_INCLUDED_ESP8266_GCCOLLECT_H

ports/esp8266/modesp.c

@@ -259,8 +259,6 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(esp_esf_free_bufs_obj, esp_esf_free_bufs);
 // esp.set_native_code_location() function; see below.  If flash is selected
 // then it is erased as needed.
 
-#include "gccollect.h"
-
 #define IRAM1_END (0x40108000)
 #define FLASH_START (0x40200000)
 #define FLASH_END (0x40300000)
@@ -284,16 +282,6 @@ void esp_native_code_init(void) {
     esp_native_code_erased = 0;
 }
 
-void esp_native_code_gc_collect(void) {
-    void *src;
-    if (esp_native_code_location == ESP_NATIVE_CODE_IRAM1) {
-        src = (void*)esp_native_code_start;
-    } else {
-        src = (void*)(FLASH_START + esp_native_code_start);
-    }
-    gc_collect_root(src, (esp_native_code_end - esp_native_code_start) / sizeof(uint32_t));
-}
-
 void *esp_native_code_commit(void *buf, size_t len) {
     //printf("COMMIT(buf=%p, len=%u, start=%08x, cur=%08x, end=%08x, erased=%08x)\n", buf, len, esp_native_code_start, esp_native_code_cur, esp_native_code_end, esp_native_code_erased);