Create local C library implementation (2/2)

- This change is split into two separate patches in order to
  simplify the history as interpreted by 'git'. The split is
  between the move/rename and addition of new files.
- Remove dependency on toolchain C library headers and functions in
  order to ensure behavioural compatibility between toolchains.
- Use FreeBSD as reference for C library implementation.
- Do not let GCC use default library include paths.
- Remove unused definitions in modified headers and implementations.
- Move C library files to 'lib/stdlib' and 'include/stdlib'.
- Break std.c functions out into separate files.

Change-Id: I3e3d8d992052264d2a02489034ae4c03bf0f5512
diff --git a/include/stdlib/sys/stdint.h b/include/stdlib/sys/stdint.h
new file mode 100644
index 0000000..aa5ac81
--- /dev/null
+++ b/include/stdlib/sys/stdint.h
@@ -0,0 +1,74 @@
+/*-
+ * Copyright (c) 2001 Mike Barcroft <mike@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_STDINT_H_
+#define _SYS_STDINT_H_
+
+#include <sys/cdefs.h>
+#include <sys/_types.h>
+
+#include <machine/_stdint.h>
+#include <sys/_stdint.h>
+
+typedef	__int_least8_t		int_least8_t;
+typedef	__int_least16_t		int_least16_t;
+typedef	__int_least32_t		int_least32_t;
+typedef	__int_least64_t		int_least64_t;
+
+typedef	__uint_least8_t		uint_least8_t;
+typedef	__uint_least16_t	uint_least16_t;
+typedef	__uint_least32_t	uint_least32_t;
+typedef	__uint_least64_t	uint_least64_t;
+
+typedef	__int_fast8_t		int_fast8_t;
+typedef	__int_fast16_t		int_fast16_t;
+typedef	__int_fast32_t		int_fast32_t;
+typedef	__int_fast64_t		int_fast64_t;
+
+typedef	__uint_fast8_t		uint_fast8_t;
+typedef	__uint_fast16_t		uint_fast16_t;
+typedef	__uint_fast32_t		uint_fast32_t;
+typedef	__uint_fast64_t		uint_fast64_t;
+
+#ifndef _INTMAX_T_DECLARED
+typedef	__intmax_t		intmax_t;
+#define	_INTMAX_T_DECLARED
+#endif
+#ifndef _UINTMAX_T_DECLARED
+typedef	__uintmax_t		uintmax_t;
+#define	_UINTMAX_T_DECLARED
+#endif
+
+/* GNU and Darwin define this and people seem to think it's portable */
+#if defined(UINTPTR_MAX) && defined(UINT64_MAX) && (UINTPTR_MAX == UINT64_MAX)
+#define	__WORDSIZE		64
+#else
+#define	__WORDSIZE		32
+#endif
+
+#endif /* !_SYS_STDINT_H_ */