Extract initialization logic from jemalloc.c into jemalloc_init module

include/jemalloc/internal/jemalloc_init.h

@@ -0,0 +1,42 @@
+#ifndef JEMALLOC_INTERNAL_JEMALLOC_INIT_H
+#define JEMALLOC_INTERNAL_JEMALLOC_INIT_H
+
+enum malloc_init_e {
+	malloc_init_uninitialized = 3,
+	malloc_init_a0_initialized = 2,
+	malloc_init_recursible = 1,
+	malloc_init_initialized = 0 /* Common case --> jnz. */
+};
+typedef enum malloc_init_e malloc_init_t;
+
+extern malloc_init_t malloc_init_state;
+
+bool malloc_is_initializer(void);
+bool malloc_initializer_is_set(void);
+void malloc_initializer_set(void);
+
+bool malloc_init_hard_a0(void);
+bool malloc_init_hard(void);
+
+JEMALLOC_ALWAYS_INLINE bool
+malloc_init_a0(void) {
+	if (unlikely(malloc_init_state == malloc_init_uninitialized)) {
+		return malloc_init_hard_a0();
+	}
+	return false;
+}
+
+JEMALLOC_ALWAYS_INLINE bool
+malloc_initialized(void) {
+	return (malloc_init_state == malloc_init_initialized);
+}
+
+JEMALLOC_ALWAYS_INLINE bool
+malloc_init(void) {
+	if (unlikely(!malloc_initialized()) && malloc_init_hard()) {
+		return true;
+	}
+	return false;
+}
+
+#endif /* JEMALLOC_INTERNAL_JEMALLOC_INIT_H */