arm-xo-1.75: implement strlen()

Fixes build:

  Linking cforth.elf ...
  arm-none-eabi-ld: tembed.o: in function `complete_word':
  /home/lkundrak/src/cforth/build/arm-xo-1.75/../../src/cforth/lineedit.c:307: undefined reference to `strlen'
  arm-none-eabi-ld: tembed.o: in function `propose_word':
  /home/lkundrak/src/cforth/build/arm-xo-1.75/../../src/cforth/lineedit.c:349: undefined reference to `strlen'
  make: *** [../../src/platform/arm-xo-1.75/targets.mk:60: cforth.elf] Error 1

1 files changed, 8 insertions, 0 deletions

diff --git a/src/platform/arm-xo-1.75/consoleio.c b/src/platform/arm-xo-1.75/consoleio.c
index dee7ad9..7a2845b 100644
--- a/src/platform/arm-xo-1.75/consoleio.c
+++ b/src/platform/arm-xo-1.75/consoleio.c
@@ -1118,3 +1118,11 @@ void gamekey_handle(int is_timer)
 	sched_debounce();
     }
 }
+
+int strlen(const char *s)
+{
+        const char *p;
+        for (p=s; *p != '\0'; *p++) {
+        }
+        return p-s;
+}