Intel: Do not use MSVC-like flags for Fortran

Teach `Modules/Platform/Windows-MSVC.cmake` not to use MSVC options
for Fortran.  We use the `__windows_compiler_msvc` for the Intel
Fortran compiler on Windows for other settings, but we do not want
the flags.

Previously this worked only because the options were later overridden
by `Modules/Platform/Windows-Intel*.cmake`, but it is cleaner to not
set the options in the first place.

Modules/Platform/Windows-MSVC.cmake

@@ -298,20 +298,23 @@ macro(__windows_compiler_msvc lang)
   set(CMAKE_${lang}_LINK_EXECUTABLE
     "${_CMAKE_VS_LINK_EXE}<CMAKE_LINKER> ${CMAKE_CL_NOLOGO} <OBJECTS> ${CMAKE_START_TEMP_FILE} /out:<TARGET> /implib:<TARGET_IMPLIB> /pdb:<TARGET_PDB> /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR>${_PLATFORM_LINK_FLAGS} <CMAKE_${lang}_LINK_FLAGS> <LINK_FLAGS> <LINK_LIBRARIES>${CMAKE_END_TEMP_FILE}")
 
-  if(CMAKE_VS_PLATFORM_TOOLSET MATCHES "v[0-9]+_clang_.*")
-    # note: MSVC 14 2015 Update 1 sets -fno-ms-compatibility by default, but this does not allow one to compile many projects
-    # that include MS's own headers. CMake itself is affected project too.
-    set(CMAKE_${lang}_FLAGS_INIT "${_PLATFORM_DEFINES}${_PLATFORM_DEFINES_${lang}} -fms-extensions -fms-compatibility -D_WINDOWS -Wall${_FLAGS_${lang}}")
-    set(CMAKE_${lang}_FLAGS_DEBUG_INIT "-D_DEBUG /MDd -gline-tables-only -fno-inline -O0 ${_RTC1}")
-    set(CMAKE_${lang}_FLAGS_RELEASE_INIT "/MD -O2 -DNDEBUG")
-    set(CMAKE_${lang}_FLAGS_RELWITHDEBINFO_INIT "/MD -gline-tables-only -O2 -fno-inline -DNDEBUG")
-    set(CMAKE_${lang}_FLAGS_MINSIZEREL_INIT "/MD -DNDEBUG") # TODO: Add '-Os' once VS generator maps it properly for Clang
-  else()
-    set(CMAKE_${lang}_FLAGS_INIT "${_PLATFORM_DEFINES}${_PLATFORM_DEFINES_${lang}} /D_WINDOWS /W3${_FLAGS_${lang}}")
-    set(CMAKE_${lang}_FLAGS_DEBUG_INIT "/D_DEBUG /MDd /Zi /Ob0 /Od ${_RTC1}")
-    set(CMAKE_${lang}_FLAGS_RELEASE_INIT "/MD /O2 /Ob2 /DNDEBUG")
-    set(CMAKE_${lang}_FLAGS_RELWITHDEBINFO_INIT "/MD /Zi /O2 /Ob1 /DNDEBUG")
-    set(CMAKE_${lang}_FLAGS_MINSIZEREL_INIT "/MD /O1 /Ob1 /DNDEBUG")
+  if("x${lang}" STREQUAL "xC" OR
+      "x${lang}" STREQUAL "xCXX")
+    if(CMAKE_VS_PLATFORM_TOOLSET MATCHES "v[0-9]+_clang_.*")
+      # note: MSVC 14 2015 Update 1 sets -fno-ms-compatibility by default, but this does not allow one to compile many projects
+      # that include MS's own headers. CMake itself is affected project too.
+      set(CMAKE_${lang}_FLAGS_INIT "${_PLATFORM_DEFINES}${_PLATFORM_DEFINES_${lang}} -fms-extensions -fms-compatibility -D_WINDOWS -Wall${_FLAGS_${lang}}")
+      set(CMAKE_${lang}_FLAGS_DEBUG_INIT "-D_DEBUG /MDd -gline-tables-only -fno-inline -O0 ${_RTC1}")
+      set(CMAKE_${lang}_FLAGS_RELEASE_INIT "/MD -O2 -DNDEBUG")
+      set(CMAKE_${lang}_FLAGS_RELWITHDEBINFO_INIT "/MD -gline-tables-only -O2 -fno-inline -DNDEBUG")
+      set(CMAKE_${lang}_FLAGS_MINSIZEREL_INIT "/MD -DNDEBUG") # TODO: Add '-Os' once VS generator maps it properly for Clang
+    else()
+      set(CMAKE_${lang}_FLAGS_INIT "${_PLATFORM_DEFINES}${_PLATFORM_DEFINES_${lang}} /D_WINDOWS /W3${_FLAGS_${lang}}")
+      set(CMAKE_${lang}_FLAGS_DEBUG_INIT "/D_DEBUG /MDd /Zi /Ob0 /Od ${_RTC1}")
+      set(CMAKE_${lang}_FLAGS_RELEASE_INIT "/MD /O2 /Ob2 /DNDEBUG")
+      set(CMAKE_${lang}_FLAGS_RELWITHDEBINFO_INIT "/MD /Zi /O2 /Ob1 /DNDEBUG")
+      set(CMAKE_${lang}_FLAGS_MINSIZEREL_INIT "/MD /O1 /Ob1 /DNDEBUG")
+    endif()
   endif()
   set(CMAKE_${lang}_LINKER_SUPPORTS_PDB ON)
   set(CMAKE_NINJA_DEPTYPE_${lang} msvc)