Don't override CC and CXX on Windows when set, handle ccache.

This is to allow use of ccache by specifying something like:

  export CC="ccache C:/path/to/cl.exe"
  export CXX="ccache C:/patch/to/cl.exe"

before running ./autogen.sh

configure.in

@@ -2131,7 +2131,7 @@ if test "$_os" = "WINNT"; then
         else
             with_cl_home=`cygpath -u "$with_cl_home"`
         fi
-        AC_MSG_RESULT([done])
+        AC_MSG_RESULT([$with_cl_home])
 
         dnl ===========================================================
         dnl  Check for mspdb80.dll/mspdb100.dll
@@ -2172,27 +2172,29 @@ if test "$_os" = "WINNT"; then
         PATH="$MSPDB_PATH:$PATH"
 
         AC_MSG_CHECKING([the Microsoft C/C++ Compiler])
-        if test "$CL_X64" = ""; then
-            if test -x "$with_cl_home/bin/cl.exe"; then
-                CC="$with_cl_home/bin/cl.exe"
+        if test -z "$CC"; then
+            if test "$CL_X64" = ""; then
+                if test -x "$with_cl_home/bin/cl.exe"; then
+                    CC="$with_cl_home/bin/cl.exe"
+                fi
+            else
+                if test -x "$with_cl_home/bin/amd64/cl.exe"; then
+                    CC="$with_cl_home/bin/amd64/cl.exe"
+                fi
             fi
-        else
-            if test -x "$with_cl_home/bin/amd64/cl.exe"; then
-                CC="$with_cl_home/bin/amd64/cl.exe"
+            if test -z "$CC"; then
+                AC_PATH_PROG(CC, cl.exe)
             fi
-        fi
-        if test -z "$CC"; then
-            AC_PATH_PROG(CC, cl.exe)
-        fi
-
-          if test -e "$CC"; then
             # This gives us a posix path with 8.3 filename restrictions
             CC=`cygpath -d "$CC"`
             CC=`cygpath -u "$CC"`
+        fi
+
+        if test -n "$CC"; then
             # Remove /cl.exe from CC case insensitive
             AC_MSG_RESULT([found ($CC)])
             if test "$CL_X64" = ""; then
-                COMPATH=`echo $CC | $SED 's@\/[[Bb]][[Ii]][[Nn]]\/[[cC]][[lL]]\.[[eE]][[xX]][[eE]]@@'`
+                COMPATH=`echo $CC | $SED -e 's@\/[[Bb]][[Ii]][[Nn]]\/[[cC]][[lL]]\.[[eE]][[xX]][[eE]].*@@' -e 's@^.* @@'`
             else
                 if test -n "$with_cl_home"; then
                     COMPATH=`echo $with_cl_home`
@@ -2427,7 +2429,7 @@ dnl ===================================================================
 dnl Testing for c++ compiler and version...
 dnl ===================================================================
 if test "$_os" = "WINNT" -a "$WITH_MINGW" != "yes"; then
-   if test -e "$CC"; then
+   if test -n "$CC" -a -z "$CXX"; then
       CXX="$CC"
    fi
 fi

set_soenv.in

@@ -125,12 +125,8 @@ $JDK 		= '@JDK@';
 $JAVAFLAGS 		= '@JAVAFLAGS@';
 $MINGW          = '@WITH_MINGW@';    # use MinGW for Windows build
 $USE_MINGW      = '@USE_MINGW@';     # use MinGW in cygwin or pure-mingw
-if ( $MINGW eq "yes" )
-{ $CC             = '@CC@';           # C compiler
-  $CXX            = '@CXX@'; }        # C++ compiler
-else
-{ $CC             = PathFormat('@CC@');           # C compiler
-  $CXX            = PathFormat('@CXX@'); }        # C++ compiler
+$CC             = '@CC@';            # C compiler
+$CXX            = '@CXX@';           # C++ compiler
 $MOZILLA_VERSION	= '@MOZILLA_VERSION@'; # mozilla version to use to build mozilla
 $MOZILLA_TOOLKIT	= '@MOZILLA_TOOLKIT@'; # GUI toolkit to use to build mozilla
 $FLIPCMD        = "";               # Flip '/' to '\' wrapper (only for winnt)