Sync with the latest changes to Arduino platform.txt

Author: ivankravets

tools/platformio-build.py

@@ -38,6 +38,7 @@
  CPPDEFINES=[
  ("ARDUINO", 10805),
  "ARDUINO_ARCH_ESP32",
+ ("ARDUINO_VARIANT", '\\"%s\\"' % env.BoardConfig().get("build.variant").replace('"', "")),
  ("ARDUINO_BOARD", '\\"%s\\"' % env.BoardConfig().get("name").replace('"', ""))
  ],
 
@@ -174,7 +175,7 @@ def _get_board_flash_mode(env):
  join(FRAMEWORK_DIR, "cores", env.BoardConfig().get("build.core"))
 ))
 
-env.Append(LIBS=libs)
+env.Prepend(LIBS=libs)
 
 #
 # Generate partition table