libsysprof-capture: add sysprof_getpagesize()

This is a helper to get the page size on various platforms so that calling
code does not need to duplicate that effort.

src/libsysprof-capture/sysprof-platform.c

@@ -63,6 +63,7 @@
 #include <sys/syscall.h>
 #include <unistd.h>
 
+#include "sysprof-capture-util-private.h"
 #include "sysprof-platform.h"
 
 /**
@@ -105,3 +106,18 @@ sysprof_memfd_create (const gchar *name)
   return fd;
 #endif
 }
+
+/**
+ * sysprof_getpagesize:
+ *
+ * Gets the page size using platform specific APIs.
+ *
+ * Returns: the system page size
+ *
+ * Since: 3.36
+ */
+gsize
+sysprof_getpagesize (void)
+{
+  return _sysprof_getpagesize ();
+}

src/libsysprof-capture/sysprof-platform.h

@@ -61,6 +61,8 @@
 G_BEGIN_DECLS
 
 SYSPROF_AVAILABLE_IN_ALL
-int sysprof_memfd_create (const gchar *desc);
+int   sysprof_memfd_create (const gchar *desc);
+SYSPROF_AVAILABLE_IN_3_36
+gsize sysprof_getpagesize   (void);
 
 G_END_DECLS