{cc,bintools}-wrapper: also replace . in config

Some configs will have dots for version numbers. To normalize we can
just use _ again.

pkgs/build-support/cc-wrapper/default.nix

@@ -45,14 +45,12 @@ let
   default_cxx_stdlib_compile = optionalString (targetPlatform.isLinux && !(cc.isGNU or false) && !nativeTools && cc ? gcc)
     "-isystem $(echo -n ${cc.gcc}/include/c++/*) -isystem $(echo -n ${cc.gcc}/include/c++/*)/$(${cc.gcc}/bin/gcc -dumpmachine)";
 
-  dashlessTarget = stdenv.lib.replaceStrings ["-"] ["_"] targetPlatform.config;
-
   # The "infix salt" is a arbitrary string added in the middle of env vars
   # defined by cc-wrapper's hooks so that multiple cc-wrappers can be used
   # without interfering. For the moment, it is defined as the target triple,
   # adjusted to be a valid bash identifier. This should be considered an
   # unstable implementation detail, however.
-  infixSalt = dashlessTarget;
+  infixSalt = replaceStrings ["-" "."] ["_" "_"] targetPlatform.config;
 
   expand-response-params =
     if buildPackages.stdenv.cc or null != null && buildPackages.stdenv.cc != "/dev/null"