Merge topic 'intel-gnu11-support'

088f14eb Intel-C: standard flags are also supported in 12.0
27a3ca15 Intel-C: support gnu89 and gnu99 extension flags
cc223e1e Intel-C: declare support for gnu11

Modules/Compiler/Intel-C.cmake

@@ -15,14 +15,14 @@ endif()
 
 if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 15.0.0)
   set(CMAKE_C11_STANDARD_COMPILE_OPTION "${_std}=c11")
-  set(CMAKE_C11_EXTENSION_COMPILE_OPTION "${_std}=c11")
+  set(CMAKE_C11_EXTENSION_COMPILE_OPTION "${_std}=gnu11")
 endif()
 
-if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 12.1)
+if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 12.0)
   set(CMAKE_C90_STANDARD_COMPILE_OPTION "${_std}=c89")
-  set(CMAKE_C90_EXTENSION_COMPILE_OPTION "${_std}=c89")
+  set(CMAKE_C90_EXTENSION_COMPILE_OPTION "${_std}=gnu89")
   set(CMAKE_C99_STANDARD_COMPILE_OPTION "${_std}=c99")
-  set(CMAKE_C99_EXTENSION_COMPILE_OPTION "${_std}=c99")
+  set(CMAKE_C99_EXTENSION_COMPILE_OPTION "${_std}=gnu99")
 endif()
 
 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 12.1)