Fix compatibility with -Wl,--gc-sections.

http://www.cmake.org/pipermail/cmake/2008-August/023240.html
http://www.cmake.org/pipermail/cmake-commits/2008-August/004477.html

--- Modules/CheckTypeSizeC.c.in
+++ Modules/CheckTypeSizeC.c.in
@@ -29,15 +29,16 @@
   ('0' +  (SIZE    % 10)), 
   ']','\0'};
 
-
 #ifdef __CLASSIC_C__
-int main(){
-  int ac;
-  char*av[];
+int main(argc, argv) int argc; char *argv[];
 #else
-int main(int ac, char*av[]){
+int main(int argc, char *argv[])
 #endif
-  return (&info_sizeof[0] != &info_sizeof[0]);
+{
+  int require = 0;
+  require += info_sizeof[argc];
+  (void)argv;
+  return require;
 }
 
 #else  /* CHECK_TYPE_SIZE_TYPE */
--- Modules/CMakeCCompilerABI.c
+++ Modules/CMakeCCompilerABI.c
@@ -12,17 +12,17 @@
 
 /*--------------------------------------------------------------------------*/
 
-/* Make sure the information strings are referenced.  */
-#define REQUIRE(x) (&x[0] != &require)
-
-int main()
+#ifdef __CLASSIC_C__
+int main(argc, argv) int argc; char *argv[];
+#else
+int main(int argc, char *argv[])
+#endif
 {
-  const char require = 0;
-  return
-    (
-      REQUIRE(info_sizeof_dptr)
+  int require = 0;
+  require += info_sizeof_dptr[argc];
 #if defined(ABI_ID)
-      && REQUIRE(info_abi)
+  require += info_abi[argc];
 #endif
-      );
+  (void)argv;
+  return require;
 }
--- Modules/CMakeCCompilerId.c.in
+++ Modules/CMakeCCompilerId.c.in
@@ -2,15 +2,9 @@
 # error "A C++ compiler has been selected for C."
 #endif
 
-/* Provide main() so the program can link.  */
 #if defined(__18CXX)
 # define ID_VOID_MAIN
 #endif
-#ifdef ID_VOID_MAIN
-void main() {}
-#else
-int main() { return 0; }
-#endif
 
 #if defined(__INTEL_COMPILER) || defined(__ICC)
 # define COMPILER_ID "Intel"
@@ -82,3 +76,18 @@
 char* info_compiler = "INFO" ":" "compiler[" COMPILER_ID "]";
 
 @CMAKE_C_COMPILER_ID_PLATFORM_CONTENT@
+
+/*--------------------------------------------------------------------------*/
+
+#ifdef ID_VOID_MAIN
+void main() {}
+#else
+int main(int argc, char* argv[])
+{
+  int require = 0;
+  require += info_compiler[argc];
+  require += info_platform[argc];
+  (void)argv;
+  return require;
+}
+#endif
--- Modules/CMakeCXXCompilerABI.cpp
+++ Modules/CMakeCXXCompilerABI.cpp
@@ -8,17 +8,13 @@
 
 /*--------------------------------------------------------------------------*/
 
-/* Make sure the information strings are referenced.  */
-#define REQUIRE(x) (&x[0] != &require)
-
-int main()
+int main(int argc, char* argv[])
 {
-  const char require = 0;
-  return
-    (
-      REQUIRE(info_sizeof_dptr)
+  int require = 0;
+  require += info_sizeof_dptr[argc];
 #if defined(ABI_ID)
-      && REQUIRE(info_abi)
+  require += info_abi[argc];
 #endif
-      );
+  (void)argv;
+  return require;
 }
--- Modules/CMakeCXXCompilerId.cpp.in
+++ Modules/CMakeCXXCompilerId.cpp.in
@@ -5,9 +5,6 @@
 # error "A C compiler has been selected for C++."
 #endif
 
-/* Provide main() so the program can link.  */
-int main() { return 0; }
-
 #if defined(__COMO__)
 # define COMPILER_ID "Comeau"
 
@@ -70,3 +67,14 @@
 char* info_compiler = "INFO" ":" "compiler[" COMPILER_ID "]";
 
 @CMAKE_CXX_COMPILER_ID_PLATFORM_CONTENT@
+
+/*--------------------------------------------------------------------------*/
+
+int main(int argc, char* argv[])
+{
+  int require = 0;
+  require += info_compiler[argc];
+  require += info_platform[argc];
+  (void)argv;
+  return require;
+}
--- Modules/TestEndianess.c.in
+++ Modules/TestEndianess.c.in
@@ -10,11 +10,14 @@
 const cmakeint16 info_big[] =     {0x5448, 0x4953, 0x2049, 0x5320, 0x4249, 0x4720, 0x454e, 0x4449, 0x414e, 0x2e2e, 0x0000};
 
 #ifdef __CLASSIC_C__
-int main(){
-  int ac;
-  char*av[];
+int main(argc, argv) int argc; char *argv[];
 #else
-int main(int ac, char*av[]){
+int main(int argc, char *argv[])
 #endif
-   return (&info_little[0] != &info_big[0]);
+{
+  int require = 0;
+  require += info_little[argc];
+  require += info_big[argc];
+  (void)argv;
+  return require;
 }