build: init cmake build system for am

abstract-machine/am/src/native/CMakeLists.txt

@@ -0,0 +1,26 @@
+include(CheckPIESupported)
+check_pie_supported()
+
+set(SOURCES
+    trap.S
+    cte.c
+    ioe.c
+    mpe.c
+    platform.c
+    trm.c
+    vme.c
+    ioe/audio.c
+    ioe/disk.c
+    ioe/gpu.c
+    ioe/input.c
+    ioe/timer.c
+)
+add_library(am-native ${SOURCES})
+
+# FIXME: get free(): invalid address when user program compiled without pie
+set_target_properties(am-native PROPERTIES
+    POSITION_INDEPENDENT_CODE TRUE
+    INTERFACE_POSITION_INDEPENDENT_CODE TRUE)
+
+find_package(SDL2 REQUIRED)
+target_link_libraries(am-${ARCH} PUBLIC SDL2::SDL2)