GCC 10.3 Bugfix 1 - Constant literal address fix

See: xoseperez/espurna@4d04125
See: esp8266/Arduino#8393

Author: TD-er

platformio_core_defs.ini

@@ -136,7 +136,8 @@ build_flags               = ${esp82xx_2_6_x.build_flags}
                             -Wno-deprecated-declarations
 platform_packages = 
     platformio/framework-arduinoespressif8266 @ https://github.com/esp8266/Arduino.git
-    platformio/toolchain-xtensa @ ~2.100300.210717
+    mcspr/toolchain-xtensa @ ~5.100300.211127
+
 
 ; Updated ESP-IDF to the latest stable 4.0.1
 ; See: https://github.com/platformio/platform-espressif32/releases