oops, define cxx_ld correctly

dtool/pptempl/Template.unix.pp

@@ -313,7 +313,7 @@ igate : $[get_igatedb(metalib_target lib_target ss_lib_target)]
   #define sources \
    $[patsubst %,$[%_obj],$[compile_sources]]
   #define cc_ld $[or $[get_ld],$[CC]]
-  #define cxx_ld $[or $[get_ld],$[CC]]
+  #define cxx_ld $[or $[get_ld],$[CXX]]
 
   #define varname $[subst -,_,lib$[TARGET]_so]
 $[varname] = $[sources]
@@ -514,7 +514,7 @@ $[varname] = $[patsubst %,$[%_obj],$[compile_sources]]
 #define target $[ODIR]/$[TARGET]
 #define sources $($[varname])
 #define cc_ld $[or $[get_ld],$[CC]]
-#define cxx_ld $[or $[get_ld],$[CC]]
+#define cxx_ld $[or $[get_ld],$[CXX]]
 $[target] : $[sources] $[static_lib_dependencies]
 #if $[filter %.cxx %.yxx %.lxx,$[get_sources]]
 $[TAB] $[LINK_BIN_C++]
@@ -558,7 +558,7 @@ $[varname] = $[patsubst %,$[%_obj],$[compile_sources]]
 #define target $[ODIR]/$[TARGET]
 #define sources $($[varname])
 #define cc_ld $[or $[get_ld],$[CC]]
-#define cxx_ld $[or $[get_ld],$[CC]]
+#define cxx_ld $[or $[get_ld],$[CXX]]
 $[target] : $[sources] $[static_lib_dependencies]
 #if $[filter %.cxx %.yxx %.lxx,$[get_sources]]
 $[TAB] $[LINK_BIN_C++]