Libraries: Create top level directory for libraries.

Things were getting a little crowded in the project root, so this patch
moves the Lib*/ directories into Libraries/.

Libraries/LibC/stdlib.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include <stddef.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+__BEGIN_DECLS
+
+#define EXIT_SUCCESS 0
+#define EXIT_FAILURE 1
+#define MB_CUR_MAX 1
+
+__attribute__((malloc)) __attribute__((alloc_size(1))) void* malloc(size_t);
+__attribute__((malloc)) __attribute__((alloc_size(1, 2))) void* calloc(size_t nmemb, size_t);
+size_t malloc_size(void*);
+void free(void*);
+void* realloc(void* ptr, size_t);
+char* getenv(const char* name);
+int putenv(char*);
+int unsetenv(const char*);
+int setenv(const char* name, const char* value, int overwrite);
+int atoi(const char*);
+long atol(const char*);
+long long atoll(const char*);
+double strtod(const char*, char** endptr);
+float strtof(const char*, char** endptr);
+long strtol(const char*, char** endptr, int base);
+unsigned long strtoul(const char*, char** endptr, int base);
+void qsort(void* base, size_t nmemb, size_t size, int (*compar)(const void*, const void*));
+void qsort_r(void* base, size_t nmemb, size_t size, int (*compar)(const void*, const void*, void*), void* arg);
+int atexit(void (*function)());
+__attribute__((noreturn)) void exit(int status);
+__attribute__((noreturn)) void abort();
+char* ptsname(int fd);
+int ptsname_r(int fd, char* buffer, size_t);
+int abs(int);
+long labs(long);
+double atof(const char*);
+int system(const char* command);
+char* mktemp(char*);
+void* bsearch(const void* key, const void* base, size_t nmemb, size_t size, int (*compar)(const void*, const void*));
+
+#define RAND_MAX 32767
+int rand();
+void srand(unsigned seed);
+
+long int random();
+void srandom(unsigned seed);
+
+typedef struct {
+    int quot;
+    int rem;
+} div_t;
+div_t div(int, int);
+typedef struct {
+    long quot;
+    long rem;
+} ldiv_t;
+ldiv_t ldiv(long, long);
+
+__END_DECLS