build: various cmake fixes

- silence false warnings on MSVC
- merge `clang-tidy` cmake target into `lintc` and remove the
  corresponding make target
- use cmake's built-in endianness detection

cmake.config/CMakeLists.txt

@@ -4,6 +4,7 @@ include(CheckFunctionExists)
 include(CheckIncludeFiles)
 include(CheckCSourceRuns)
 include(CheckCSourceCompiles)
+include(TestBigEndian)
 
 check_c_source_compiles("
 #include <execinfo.h>
@@ -130,31 +131,8 @@ endif()
 if("${HAVE_BE64TOH_MACROS}" OR "${HAVE_BE64TOH_FUNC}")
   set(HAVE_BE64TOH 1)
 endif()
-if (NOT "${HAVE_BE64TOH}")
-  if (NOT "${CMAKE_CROSSCOMPILING}")
-    # It is safe to make ORDER_BIG_ENDIAN not defined if
-    # - HAVE_BE64TOH is true. In this case be64toh will be used unconditionally in
-    #   any case and ORDER_BIG_ENDIAN will not be examined.
-    # - CMAKE_CROSSCOMPILING *and* HAVE_BE64TOH are both false. In this case
-    #   be64toh function which uses cycle and arithmetic operations is used which
-    #   will work regardless of endianness. Function is sub-optimal though.
-    check_c_source_runs("
-      ${SI}
-      ${MS}
-        char *s = (char *) &i;
-        return (
-          s[0] == 0x01
-          && s[1] == 0x02
-          && s[2] == 0x03
-          && s[3] == 0x04
-          && s[4] == 0x05
-          && s[5] == 0x06
-          && s[6] == 0x07
-          && s[7] == 0x08) ? 0 : 1;
-      ${ME}"
-      ORDER_BIG_ENDIAN)
-  endif()
-endif()
+
+test_big_endian(ORDER_BIG_ENDIAN)
 
 configure_file (
   "${PROJECT_SOURCE_DIR}/cmake.config/config.h.in"