meson: check for reallocarray

it is needed for the new cache code

libpkgconf/config.h.meson

@@ -9,6 +9,9 @@
 /* Define to 1 if you have the `strndup' function. */
 #mesondefine HAVE_STRNDUP
 
+/* Define to 1 if you have the `reallocarray' function. */
+#mesondefine HAVE_REALLOCARRAY
+
 /* Name of package */
 #mesondefine PACKAGE
 

meson.build

@@ -16,6 +16,7 @@ check_functions = [
   ['HAVE_STRDUP', 'strdup', 'string.h'],
   ['HAVE_STRNCASECMP', 'strncasecmp', 'strings.h'],
   ['HAVE_STRCASECMP', 'strcasecmp', 'strings.h'],
+  ['HAVE_REALLOCARRAY', 'reallocarray', 'stdlib.h'],
 ]
 
 foreach f : check_functions