crt: Add emulation of _get_daylight() function for pre-msvcr80 import libs

Function _get_daylight() is available in msvcr80+ and UCRT.

Signed-off-by: Martin Storsjö <martin@martin.st>
diff --git a/mingw-w64-crt/Makefile.am b/mingw-w64-crt/Makefile.am
index 021b92c..6f04933 100644
--- a/mingw-w64-crt/Makefile.am
+++ b/mingw-w64-crt/Makefile.am
@@ -332,6 +332,7 @@
   misc/_aligned_offset_recalloc.c \
   misc/_aligned_recalloc.c \
   misc/_configthreadlocale.c \
+  misc/_get_daylight.c \
   misc/_recalloc.c \
   misc/_set_purecall_handler.c \
   misc/imaxdiv.c \
@@ -877,6 +878,7 @@
   misc/_aligned_offset_recalloc.c \
   misc/_aligned_recalloc.c \
   misc/_configthreadlocale.c \
+  misc/_get_daylight.c \
   misc/_get_errno.c \
   misc/_initterm_e.c \
   misc/_recalloc.c \
diff --git a/mingw-w64-crt/misc/_get_daylight.c b/mingw-w64-crt/misc/_get_daylight.c
new file mode 100644
index 0000000..4db7b27
--- /dev/null
+++ b/mingw-w64-crt/misc/_get_daylight.c
@@ -0,0 +1,20 @@
+/**
+ * This file has no copyright assigned and is placed in the Public Domain.
+ * This file is part of the mingw-w64 runtime package.
+ * No warranty is given; refer to the file DISCLAIMER.PD within this package.
+ */
+#include <time.h>
+#include <errno.h>
+
+errno_t __cdecl _get_daylight(int *value)
+{
+  if (!value)
+  {
+    errno = EINVAL;
+    return EINVAL;
+  }
+
+  *value = _daylight;
+  return 0;
+}
+errno_t (__cdecl *__MINGW_IMP_SYMBOL(_get_daylight))(int *) = _get_daylight;