win32/regex: fix compile warnings

There are plenty of warnings that were not detected in Git's source
code, due to some warnings being turned off in Git's build by default
(even with DEVELOPER=1).

The warnings fall into three categories:

- constants being tested via `#if <name>` instead of `#ifdef <name>`

- unused function parameters

- one instance of an unnecessarily-shadowing variable

This patch fixes all of them.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/win32/regex_internal.h b/win32/regex_internal.h
index 4184d7f5a..1495059ab 100644
--- a/win32/regex_internal.h
+++ b/win32/regex_internal.h
@@ -115,7 +115,7 @@ is_blank (int c)
 #define MB_CUR_MAX 1
 #endif
 
-#if (defined MBS_SUPPORT) || _LIBC
+#if (defined MBS_SUPPORT) || defined _LIBC
 # define RE_ENABLE_I18N
 #endif
 
@@ -454,7 +454,7 @@ static unsigned int re_string_context_at (const re_string_t *input, int idx,
 
 #ifndef _LIBC
 # if HAVE_ALLOCA
-#  if (_MSC_VER)
+#  ifdef (_MSC_VER)
 #   include <malloc.h>
 #   define __libc_use_alloca(n) 0
 #  else