Add a UTF-8 resource when building for Windows

If a resource compiler is available, use it to add a UTF-8 resource
to the GNU Make executable on Windows.  As a result, GNU Make will
use UTF-8 as its ANSI code page, enabling it to work with UTF-8
encoded Makefiles, understand UTF-8 paths passed to it, etc.

These build process changes apply to all 3 ways that GNU Make can
be built for Windows:

1) configure
2) Basic.mk
3) build_w32.bat

When building with Visual Studio the resource compiler should always
be available.

When building with GCC or TCC, it depends on the availability of
'windres'.

If a resource compiler is not available, don't fail the build but
just proceed without the UTF-8 resource, effectively ignoring this
feature.

The UTF-8 resource only has an effect when GNU Make is running on a
minimum target version of Windows Version 1903 (May 2019 Update).
When the built GNU Make is running on an earlier version of Windows,
the embedded UTF-8 resource has no effect.

Code page information is added to --version output to tell users what
code pages are being used by any combination of GNU Make build (with
or without the UTF-8 resource) and Windows version that GNU Make is
running on (earlier than 1903 or not).

* README.git: Fix a typo.
* configure.ac: Search for windres and set WINDRES / HAVE_WINDRES.
* Makefile.am: Add manifest and resource files to EXTRA_DIST and
add a windres invocation to build them.
* build_w32.bat: Add support to build resource files.
* src/main.c (print_version): Add codepage info to Windows output.
* src/w32/utf8.manifest: Add a windres manifest file.
* src/w32/utf8.rc: Add a windres resource file.
* Basic.mk.template: Add support for building resource files.
* mk/Windows32.mk: Support windres resource files.
* .gitignore: Ignore TCC output directories.

src/main.c

@@ -3708,6 +3708,11 @@ print_version (void)
     printf (_("%sBuilt for %s (%s)\n"),
             precede, make_host, remote_description);
 
+#if MK_OS_W32
+  printf (_("%sANSI code page: %u\n"), precede, GetACP ());
+  printf (_("%sConsole code page: %u\n"), precede, GetConsoleOutputCP ());
+#endif
+
   /* Print this untranslated.  The coding standards recommend translating the
      (C) to the copyright symbol, but this string is going to change every
      year, and none of the rest of it should be translated (including the

src/w32/utf8.manifest

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <application>
+    <windowsSettings>
+      <activeCodePage xmlns="http://schemas.microsoft.com/SMI/2019/WindowsSettings">UTF-8</activeCodePage>
+    </windowsSettings>
+  </application>
+</assembly>

src/w32/utf8.rc

@@ -0,0 +1,3 @@
+#include <winuser.h>
+
+CREATEPROCESS_MANIFEST_RESOURCE_ID RT_MANIFEST "utf8.manifest"