STYLE: provide WM_CC, WM_CXX values for Icc.

- since Icc is actually mentioned in bashrc/cshrc it is consistent to
  set these values accordingly.

etc/config.csh/compiler

@@ -90,6 +90,10 @@ case Clang:
     setenv WM_CC 'clang'
     setenv WM_CXX 'clang++'
     breaksw
+case Icc:
+    setenv WM_CC 'icc'
+    setenv WM_CXX 'icpc'
+    breaksw
 endsw
 
 #------------------------------------------------------------------------------

etc/config.sh/compiler

@@ -87,6 +87,10 @@ Clang)
     export WM_CC='clang'
     export WM_CXX='clang++'
     ;;
+Icc)
+    export WM_CC='icc'
+    export WM_CXX='icpc'
+    ;;
 esac
 
 #------------------------------------------------------------------------------