fixup! mingw: add a cache below mingw's lstat and dirent implementations

Back when the FSCache was invented, there was no way to ask Windows to
store filenames case-sensitively. Also, `fspathcmp()` had not been
invented yet, so we simply used `strnicmp()` to compare the filenames in
the FSCache.

In the meantime, much has changed.

Let's use `fspathncmp()` instead, and benefit from case-sensitive file
names as configured.

Note: to make use of this, users _must_ call `fsutil.exe file
setCaseSensitiveInfo .` in an empty directory _before_ calling `git
init` to allow Git to detect that filenames are stored case-sensitively.

This fixes #3686

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

compat/win32/fscache.c

@@ -5,6 +5,7 @@
 #include "config.h"
 #include "../../mem-pool.h"
 #include "ntifs.h"
+#include "../../dir.h"
 
 static volatile long initialized;
 static DWORD dwTlsIndex;
@@ -101,7 +102,7 @@ static int fsentry_cmp(void *unused_cmp_data,
 	/* if list parts are equal, compare len and name */
 	if (fse1->len != fse2->len)
 		return fse1->len - fse2->len;
-	return strnicmp(fse1->dirent.d_name, fse2->dirent.d_name, fse1->len);
+	return fspathncmp(fse1->dirent.d_name, fse2->dirent.d_name, fse1->len);
 }
 
 /*