Refactor SDL/FreeRTOS implementation to support macOS simulator properly (#653)

- Run SDL from main() and place FreeRTOS in separate thread. This fixes macOS support.
- Updated GitHub Actions to publish macOS simulator build for testing, updated amd64 to x86_64 for consistent naming.

Tactility/Tests/CMakeLists.txt

@@ -19,18 +19,9 @@ target_include_directories(TactilityTests PRIVATE ${CMAKE_CURRENT_LIST_DIR}/../P
 
 add_test(NAME TactilityTests COMMAND TactilityTests)
 
-# Matches Tactility/CMakeLists.txt's own set of --wrap flags: this binary also compiles
-# AppStdioWrap.cpp and links app-module (whose io.cpp calls __real_read/write/close() on
-# non-Apple POSIX - see TT_APP_IO_WRAPS_STDIO in Modules/app-module/CMakeLists.txt), so it
-# needs the same wraps applied or those go unresolved.
-if (NOT APPLE)
-    target_link_options(TactilityTests PRIVATE
-        "-Wl,--wrap=pthread_attr_setstack" "-Wl,--wrap=read" "-Wl,--wrap=write" "-Wl,--wrap=close"
-        "-Wl,--wrap=printf" "-Wl,--wrap=fprintf" "-Wl,--wrap=vprintf" "-Wl,--wrap=vfprintf"
-        "-Wl,--wrap=puts" "-Wl,--wrap=fputs" "-Wl,--wrap=putchar" "-Wl,--wrap=fputc"
-        "-Wl,--wrap=getchar" "-Wl,--wrap=fgetc" "-Wl,--wrap=fgets"
-    )
-endif ()
+# No --wrap flags declared here: linking platform-posix and app-module below already brings all
+# of pthread_attr_setstack/read/write/close/the printf family along (see their own CMakeLists.txt
+# files).
 
 target_link_libraries(TactilityTests PRIVATE
     TactilityKernel