meta: replace cmake mono-build system with a custom build co-ordinator

every system component now has its own self-contained build system, and a
seed file describing the component and its build system and dependencies.

a new tool, meadow, collects and uses these seed files to build the
components into a full system. meadow also manages the target system root
and a host prefix where toolchain tools are installed to.

the build system has also been updated to use a new $ARCH-rosetta-gcc
compiler, and the patches files necessary to build it have been
added to toolchain/cross-compiler.

lib/libc/core/CMakeLists.txt

@@ -1,3 +1,8 @@
+if (LIBC_STANDALONE)
+	cmake_minimum_required(VERSION 3.31)
+	project(libc-core C ASM)
+endif ()
+
 set(source_dirs assert stdio stdlib string errno ctype wctype unistd)
 
 foreach (dir ${source_dirs})
@@ -12,18 +17,16 @@ file(GLOB sys_sources
 	${CMAKE_CURRENT_SOURCE_DIR}/sys/${CMAKE_SYSTEM_PROCESSOR}/*.c
 	${CMAKE_CURRENT_SOURCE_DIR}/sys/${CMAKE_SYSTEM_PROCESSOR}/*.S)
 
-set(component_sources ${sources} ${sys_sources} PARENT_SCOPE)
-set(component_headers ${headers} PARENT_SCOPE)
-
-rosetta_add_library(STATIC
-	NAME libc-core
-	PUBLIC_INCLUDE_DIRS ${public_include_dirs}
-	SOURCES ${sources} ${sys_sources}
-	HEADERS ${headers})
-
-sysroot_add_library(
-	NAME libc-core
-	HEADER_DIR /usr/include
-	LIB_DIR /usr/lib)
+if (NOT LIBC_STANDALONE)
+	set(component_sources ${sources} ${sys_sources} PARENT_SCOPE)
+	set(component_headers ${headers} PARENT_SCOPE)
+	return ()
+endif ()
 
+add_library(libc-core STATIC ${sources} ${sys_sources} ${headers})
+target_include_directories(libc-core PUBLIC ${public_include_dirs})
 target_link_libraries(libc-core PRIVATE libmagenta librosetta)
+target_compile_definitions(libc-core PRIVATE ENABLE_GLOBAL_HEAP=1 BUILD_STATIC=1)
+set_target_properties(libc-core PROPERTIES
+	PREFIX "")
+install(TARGETS libc-core)