use case-insensitive search for ".exe" in Windows

original commit: 20f86fea125ecf41b2246ad3ba9e9bb3f8a79c04

LOG

@@ -1393,3 +1393,5 @@
     compress-io.c, new-io.c
 - fixed tab character in makefiles
     c/Mf-*nt
+- use case-insensitive search for ".exe" on Windows
+    c/scheme.c

c/scheme.c

@@ -1107,7 +1107,7 @@ extern void Sbuild_heap(kernel, custom_init) const char *kernel; void (*custom_i
       iptr n;
 
       n = strlen(name) - 4;
-      if (n >= 0 && (strcmp(name + n, ".exe") == 0 || strcmp(name + n, ".EXE") == 0)) {
+      if (n >= 0 && (_stricmp(name + n, ".exe") == 0)) {
         strcpy(buf, name);
         buf[n] = 0;
         name = buf;