Error out early if the architecture is not supported

CMakeLists.txt

@@ -75,13 +75,15 @@ if (${CMAKE_SYSTEM_PROCESSOR} STREQUAL "aarch64")
  set(PRELOAD_LIBRARY_PAGE_SIZE 65536)
  set(VDSO_NAME "LINUX_2.6.39")
  set(VDSO_SYMBOLS "__kernel_clock_getres; __kernel_rt_sigreturn; __kernel_gettimeofday; __kernel_clock_gettime;")
-else()
+elseif(${CMAKE_SYSTEM_PROCESSOR} MATCHES x86|x86_64)
  set(x86ish true)
  set(has_syscallbuf true)
  set(FLAGS_COMMON "${FLAGS_COMMON} -msse2 -D__MMX__ -D__SSE__ -D__SSE2__")
  set(PRELOAD_LIBRARY_PAGE_SIZE 4096)
  set(VDSO_NAME "LINUX_2.6")
  set(VDSO_SYMBOLS "__vdso_gettimeofday; __vdso_clock_getres; __vdso_time; __vdso_clock_gettime; __vdso_getcpu;")
+else()
+ message(FATAL_ERROR "The architecture " ${CMAKE_SYSTEM_PROCESSOR} " is not yet supported")
 endif()
 configure_file(src/preload/rr_page.ld.in src/preload/rr_page.ld @ONLY)