toolchain: add support of ARC architecture

This includes binutils, gcc, gdb and uClibc-ng.

Latest release of ARC gcc (as of today it is "arc-2015.06")
is based on upstream gcc 4.8.4.

Sources are available on GitHub, see:
https://github.com/foss-for-synopsys-dwc-arc-processors/gcc

Latest release of ARC binutils (as of today it is "arc-2015.06")
is based on upstream binutils 2.23.

Sources are available on GitHub, see:
https://github.com/foss-for-synopsys-dwc-arc-processors/binutils-gdb/releases/tag/arc-2015.06

Latest release of ARC GDB (as of today this is "arc-2015.06-gdb")
is based on upstream gdb 7.9.1.

Sources are available on GitHub, see:
https://github.com/foss-for-synopsys-dwc-arc-processors/binutils-gdb/releases/tag/arc-2015.06-gdb

Note that for binutils and gdb that come from unified git repository
(which is the case for upstream binutils/gdb today) we need to disable
building of gdb in binutils and binutils in gdb hence in binutils:
------>8------
--disable-sim
--disable-gdb
------>8------

and in gdb:
------>8------
--disable-binutils
--disable-ld
--disable-gas
------>8------

Also in gdb we disable sim because if the following breakage while
building with it:
------------>8------------
/usr/bin/env bash ./../common/genmloop.sh -shell /usr/bin/env bash \
        -mono -fast -pbb -switch sem5-switch.c \
        -cpu a5f -infile ./mloop5.in \
        -outfile-suffix 5
unknown option: bash
Makefile:699: recipe for target 'stamp-5mloop' failed
make[7]: *** [stamp-5mloop] Error 1
------------>8------------

Cc: Felix Fietkau <nbd@openwrt.org>
Cc: John Crispin <blogic@openwrt.org>
Cc: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@47438 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 42 insertions, 0 deletions

diff --git a/toolchain/gcc/patches/arc-2015.06/002-weak_data_fix.patch b/toolchain/gcc/patches/arc-2015.06/002-weak_data_fix.patch
new file mode 100644
index 0000000000..a740b4ce9e
--- /dev/null
+++ b/toolchain/gcc/patches/arc-2015.06/002-weak_data_fix.patch
@@ -0,0 +1,42 @@
+--- /dev/null
++++ b/gcc/testsuite/gcc.dg/visibility-21.c
+@@ -0,0 +1,14 @@
++/* PR target/32219 */
++/* { dg-do run } */
++/* { dg-require-visibility "" } */
++/* { dg-options "-fPIC" { target fpic } } */
++
++extern void f() __attribute__((weak,visibility("hidden")));
++extern int puts( char const* );
++int main()
++{
++	if (f)
++		f();
++	return 0;
++}
++
+--- a/gcc/varasm.c
++++ b/gcc/varasm.c
+@@ -6677,6 +6677,10 @@ default_binds_local_p_1 (const_tree exp,
+   /* Static variables are always local.  */
+   else if (! TREE_PUBLIC (exp))
+     local_p = true;
++  /* hidden weak can't be overridden by something non-local, all
++     that is possible is that it is not defined at all. */
++  else if (DECL_WEAK (exp))
++    local_p = false;
+   /* A variable is local if the user has said explicitly that it will
+      be.  */
+   else if ((DECL_VISIBILITY_SPECIFIED (exp)
+@@ -6690,11 +6694,6 @@ default_binds_local_p_1 (const_tree exp,
+      local.  */
+   else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
+     local_p = true;
+-  /* Default visibility weak data can be overridden by a strong symbol
+-     in another module and so are not local.  */
+-  else if (DECL_WEAK (exp)
+-	   && !resolved_locally)
+-    local_p = false;
+   /* If PIC, then assume that any global name can be overridden by
+      symbols resolved from other modules.  */
+   else if (shlib)