ARM: Compile whole tree with clang.

Note: GCC is still the default compiler, to use clang do the following:

 $ BUILDVARS="" ./releasetools/arm_sdimage.sh

sys/lib/libkern/arch/arm/Makefile.inc

@@ -0,0 +1,22 @@
+#	$NetBSD: Makefile.inc,v 1.21 2014/01/29 23:37:18 joerg Exp $
+
+SRCS+=	byte_swap_2.S byte_swap_4.S
+SRCS+=	ffs.S
+SRCS+=	memcmp.S memcpy.S memset.S memmove.S strcmp.S strncmp.S
+
+.if !empty(MACHINE_ARCH:Mearm*)
+SRCS+=	unwind_stub.c
+.endif
+.if empty(MACHINE_ARCH:Mearmv7*)
+CPUFLAGS.ffs.S+=	-marm
+.endif
+CPUFLAGS.divide.S+=	-marm
+CPUFLAGS.memcmp.S+=	-marm
+CPUFLAGS.memcpy.S+=	-marm
+CPUFLAGS.memmove.S+=	-marm
+CPUFLAGS.memset.S+=	-marm
+.if empty(CPPFLAGS:M-D_STANDALONE)
+CPUFLAGS.strcpy.S+=	-marm
+CPUFLAGS.strlcpy.S+=	-marm
+CPUFLAGS.strncpy.S+=	-marm
+.endif

sys/lib/libkern/arch/arm/unwind_stub.c

@@ -0,0 +1,48 @@
+/*-
+ * Copyright (c) 2013 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Matt Thomas of 3am Software Foundry.
+ *
+ * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+#include <sys/cdefs.h>
+__KERNEL_RCSID(1, "$NetBSD: unwind_stub.c,v 1.2 2013/08/12 23:42:14 matt Exp $");
+
+#if defined(__minix)
+#include <ehabi.h>
+#else
+#include <arm/ehabi.h>
+#endif /* defined(__minix) */
+
+static _Unwind_Reason_Code __used
+__aeabi_unwind_cpp_stub(_Unwind_State state, _Unwind_Control_Block *ucbp,
+    _Unwind_Context *context)
+{
+	return _URC_FAILURE;
+}
+
+__weak_alias(__aeabi_unwind_cpp_pr0, __aeabi_unwind_cpp_stub)
+__weak_alias(__aeabi_unwind_cpp_pr1, __aeabi_unwind_cpp_stub)
+__weak_alias(__aeabi_unwind_cpp_pr2, __aeabi_unwind_cpp_stub)

sys/lib/libunwind/Makefile.inc

@@ -16,3 +16,9 @@ CPPFLAGS.libunwind.cxx+=-I${NETBSDSRCDIR}/sys/lib/libunwind
 .if ${LIBC_MACHINE_CPU} == "arm"
 AFLAGS.unwind_registers.S+=	${${ACTIVE_CC} == "clang":? -mfpu=vfp3 :}
 .endif
+
+.if defined(__MINIX)
+.PATH:	${NETBSDSRCDIR}/sys/lib/libkern/arch/arm
+SRCS+= unwind_stub.c
+CPPFLAGS.unwind_stub.c+=-I${NETBSDSRCDIR}/sys/arch/arm/include
+.endif # defined(__MINIX)