[plt-scheme] mzc, ++ccf <flag> : Add C compiler flag

Maybe I'm mistaken, but it appears +ccf -I/opt/local/include/mysql5/ 
mysql is not passing the include path to the C compiler.

mzc -v --save-temps --debug --auto-dir ++ldf /opt/local/lib/mysql5/ 
mysql/libmysqlclient.dylib ++ccf -I/opt/local/include/mysql5/mysql  
mysqlclient.ss
mzc v371.1 [3m], Copyright (c) 2004-2007 PLT Scheme Inc.
"mysqlclient.ss":
  Reading...  expanding...
       [cpu: 98ms, real: 313ms, gc: 17ms]
  extracting core expressions
       [cpu: 51ms, real: 53ms, gc: 0ms]
  pre-processing and scanning for errors
       [cpu: 8ms, real: 14ms, gc: 0ms]
  transforming to a-normal form
       [cpu: 10ms, real: 258ms, gc: 0ms]
  determining known bindings
       [cpu: 9ms, real: 10ms, gc: 0ms]
  transforming to b-normal form, analyzing, and inlining
       [cpu: 14ms, real: 15ms, gc: 0ms]
  finding static procedures
       [cpu: 34ms, real: 34ms, gc: 22ms]
  #f [#f,#f]: Warning: found static procedure
  #f [#f,#f]: Warning: found static procedure
  #f [#f,#f]: Warning: found static procedure
  #f [#f,#f]: Warning: found static procedure
  #f [#f,#f]: Warning: found static procedure
  #f [#f,#f]: Warning: found static procedure
  #f [#f,#f]: Warning: found static procedure
  closure conversion and explicit control transformation
       [cpu: 1ms, real: 1ms, gc: 0ms]
  closure->vehicle mapping
       [cpu: 0ms, real: 1ms, gc: 0ms]
  choosing data representations
       [cpu: 0ms, real: 1ms, gc: 0ms]
  transforming to Virtual Machine form
       [cpu: 15ms, real: 15ms, gc: 0ms]
  optimizing Virtual Machine code
       [cpu: 3ms, real: 2ms, gc: 0ms]
  [emitting ANSI C to "./compiled/native/i386-macosx/3m/mysqlclient.c"]
       [cpu: 23ms, real: 24ms, gc: 0ms]
  [xforming C to "./compiled/native/i386-macosx/3m/mysqlclient3m.c"]
xform-cpp: (/usr/bin/gcc -E -DOS_X -DMZ_PRECISE_GC -I/usr/local/plt/ 
include -I/usr/local/plt/collects/compiler -DMZ_XFORM -DMZ_PRECISE_GC  
-DGC_STACK_CALLEE_RESTORE ./compiled/native/i386-macosx/3m/ 
mysqlclient.c)
./compiled/native/i386-macosx/3m/mysqlclient.c:7:19: error: mysql.h:  
No such file or directory
./compiled/native/i386-macosx/3m/mysqlclient.c:8:20: error: errmsg.h:  
No such file or directory
./compiled/native/i386-macosx/3m/mysqlclient.c:9:26: error:  
mysqld_error.h: No such file or directory
xform: cpp failed

  === context ===
/usr/local/plt/collects/compiler/private/xform.ss:8:2: xform
/usr/local/plt/collects/compiler/private/driver.ss:563:8: s:compile