espsystem: add support for RISC-V panic backtrace

Add .eh_frame and .eh_frame_hdr sections to the binary (can be
enabled/disabled within menuconfig). These sections are parsed
when a panic occurs. Their DWARF instructions are decoded and
executed at runtime, to retrieve the whole backtrace. This
parser has been tested on both RISC-V and x86 architectures.

This feature needs esptool's merge adjacent ELF sections feature.

components/bootloader_support/src/bootloader_utility.c

@@ -831,7 +831,11 @@ void bootloader_reset(void)
 
 void bootloader_atexit(void)
 {
+#ifdef BOOTLOADER_BUILD
     bootloader_console_deinit();
+#else
+    abort();
+#endif
 }
 
 esp_err_t bootloader_sha256_hex_to_str(char *out_str, const uint8_t *in_array_hex, size_t len)