Arduino.h: Correct LED_BUILTIN define order

[soburi]

Correct the order of LED_BUILTIN definitions so that board-specific
definitions of LED_BUILTIN take precedence.

[Copilot]

Pull request overview

This pull request combines two separate features: correcting the LED_BUILTIN definition order in Arduino.h to allow board-specific overrides, and adding support for board-revision-specific overlay files and improved variant directory resolution in the build system.

Changes:

• Modified Arduino.h to define LED_BUILTIN_ (with underscore) before including variant.h, then conditionally define LED_BUILTIN from LED_BUILTIN_ only if not already defined, allowing board-specific definitions to take precedence
• Updated all sample CMakeLists.txt files to support board-revision-specific overlay files with fallback to standard overlay files
• Modified main CMakeLists.txt to normalize NORMALIZED_BOARD_TARGET and support both BOARD and NORMALIZED_BOARD_TARGET variant directory paths

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 13 comments.

Show a summary per file

File	Description
cores/arduino/Arduino.h	Reorders LED_BUILTIN macro definitions to allow board-specific variant.h files to override default LED definitions
CMakeLists.txt	Adds string normalization for NORMALIZED_BOARD_TARGET and supports multiple variant directory lookup paths
samples/threads_arduino/CMakeLists.txt	Adds support for board-revision-specific overlay files with fallback
samples/spi_controller/CMakeLists.txt	Adds support for board-revision-specific overlay files with fallback
samples/serial_event/CMakeLists.txt	Adds support for board-revision-specific overlay files with fallback
samples/i2cdemo/CMakeLists.txt	Adds support for board-revision-specific overlay files with fallback
samples/hello_arduino/CMakeLists.txt	Adds support for board-revision-specific overlay files with fallback
samples/fade/CMakeLists.txt	Adds support for board-revision-specific overlay files with fallback
samples/button_press_led/CMakeLists.txt	Adds support for board-revision-specific overlay files with fallback
samples/blinky_arduino/CMakeLists.txt	Adds support for board-revision-specific overlay files with fallback
samples/attach_interrupt/CMakeLists.txt	Adds support for board-revision-specific overlay files with fallback
samples/analog_input/CMakeLists.txt	Adds support for board-revision-specific overlay files with fallback

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[pillo79]

LGTM! One small nit for your consideration.

[DhruvaG2000]

Functionality-wise we always had a ifndef LED_BUILTIN guarding this section so I am not expecting anything to change much. This approach does look cleaner now