Remove declarations of the nonstandard function strcasecmp

It is no longer used.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index 60eae9a..8f0cc2b 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -24,18 +24,12 @@
 typedef UINT8 uint8_t;
 typedef INT32 int32_t;
 typedef UINT32 uint32_t;
-#define strncasecmp _strnicmp
-#define strcasecmp _stricmp
 #else
 #include <stdint.h>
 #endif
 
 #include <string.h>
 
-#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__MINGW32__)
-#include <strings.h>
-#endif
-
 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
 #include <unistd.h>
 #endif