cs: use improved Chez Scheme call/cc

Just bumping the version number here to make sure the improved
`call/cc` is used. The improvement saves about 10% on ctak by avoiding
a layer of closure allocation.

pkgs/base/info.rkt

@@ -12,7 +12,7 @@
 
 (define collection 'multi)
 
-(define version "7.5.0.3")
+(define version "7.5.0.4")
 
 (define deps `("racket-lib"
                ["racket" #:version ,version]))

racket/src/cs/compile-file.ss

@@ -2,7 +2,7 @@
 ;; Check to make we're using a build of Chez Scheme
 ;; that has all the features we need.
 (define-values (need-maj need-min need-sub need-dev)
-  (values 9 5 3 3))
+  (values 9 5 3 4))
 
 (unless (guard (x [else #f]) (eval 'scheme-fork-version-number))
   (error 'compile-file

racket/src/racket/src/schvers.h

@@ -16,7 +16,7 @@
 #define MZSCHEME_VERSION_X 7
 #define MZSCHEME_VERSION_Y 5
 #define MZSCHEME_VERSION_Z 0
-#define MZSCHEME_VERSION_W 3
+#define MZSCHEME_VERSION_W 4
 
 /* A level of indirection makes `#` work as needed: */
 #define AS_a_STR_HELPER(x) #x