esp32: Add core dump saving to flash feature

Complimentary changes:
1) Partition table definitions files with core dump partition
2) Special sub-type for core dump partition
3) Special version of spi_flash_xxx
4) espcoredump.py is script to get core dump from flash and print useful info
5) FreeRTOS API was extended to get tasks snapshots

components/esp32/cpu_start.c

@@ -55,6 +55,7 @@
 #include "esp_task_wdt.h"
 #include "esp_phy_init.h"
 #include "esp_coexist.h"
+#include "esp_core_dump.h"
 #include "trax.h"
 
 #define STRINGIFY(s) STRINGIFY2(s)
@@ -214,6 +215,10 @@ void start_cpu0_default(void)
     }
 #endif
 
+#if CONFIG_ESP32_ENABLE_COREDUMP_TO_FLASH
+    esp_core_dump_init();
+#endif
+
     xTaskCreatePinnedToCore(&main_task, "main",
             ESP_TASK_MAIN_STACK, NULL,
             ESP_TASK_MAIN_PRIO, NULL, 0);