add initial fdpic support

binutils-2.25.1/0003-shemuls.diff is needed to include the existing
fdpic support in the build when targeting sh*-linux-* rather than
tucking it away under sh*-uclinux-* only

gcc-5.2.0/0007-fdpic.diff is based on the original abandoned fdpic
patch 3/3 sent to the gcc list in 2010, updated for modern gcc and
with the uclinux dependencies removed. the original is here:

  https://gcc.gnu.org/ml/gcc-patches/2010-08/msg01464.html

gcc-5.2.0/0001-musl.diff has been updated to use the right musl
dynamic linker pathname for fdpic so that musl-specific changes can be
avoided in the main fdpic patch.

at present, additional patches to musl are needed to produce working
binaries for the target.

patches/binutils-2.25.1/0003-shemuls.diff

@@ -0,0 +1,48 @@
+diff -ur ../baseline/binutils-2.25.1/bfd/config.bfd binutils-2.25.1/bfd/config.bfd
+--- ../baseline/binutils-2.25.1/bfd/config.bfd	2014-10-14 07:32:02.000000000 +0000
++++ binutils-2.25.1/bfd/config.bfd	2015-09-04 19:24:08.678337083 +0000
+@@ -1370,6 +1370,7 @@
+   sh-*-linux*)
+     targ_defvec=sh_elf32_linux_be_vec
+     targ_selvecs="sh_elf32_linux_vec sh64_elf32_linux_vec sh64_elf32_linux_be_vec sh64_elf64_linux_vec sh64_elf64_linux_be_vec"
++    targ_selvecs="${targ_selvecs} sh_elf32_vec sh_elf32_le_vec sh_elf32_fdpic_le_vec sh_elf32_fdpic_be_vec"
+     want64=true
+     ;;
+ #endif /* BFD64 */
+@@ -1377,10 +1378,12 @@
+   sh*eb-*-linux*)
+     targ_defvec=sh_elf32_linux_be_vec
+     targ_selvecs=sh_elf32_linux_vec
++    targ_selvecs="${targ_selvecs} sh_elf32_vec sh_elf32_le_vec sh_elf32_fdpic_le_vec sh_elf32_fdpic_be_vec"
+     ;;
+   sh*-*-linux*)
+     targ_defvec=sh_elf32_linux_vec
+     targ_selvecs=sh_elf32_linux_be_vec
++    targ_selvecs="${targ_selvecs} sh_elf32_vec sh_elf32_le_vec sh_elf32_fdpic_le_vec sh_elf32_fdpic_be_vec"
+     ;;
+ 
+   sh-*-uclinux* | sh[12]-*-uclinux*)
+diff -ur ../baseline/binutils-2.25.1/ld/configure.tgt binutils-2.25.1/ld/configure.tgt
+--- ../baseline/binutils-2.25.1/ld/configure.tgt	2014-10-14 07:32:04.000000000 +0000
++++ binutils-2.25.1/ld/configure.tgt	2015-09-04 19:22:05.151677949 +0000
+@@ -623,15 +623,17 @@
+ score-*-elf)            targ_emul=score7_elf
+ 			targ_extra_emuls=score3_elf ;;
+ sh-*-linux*)		targ_emul=shlelf_linux
+-			targ_extra_emuls=shelf_linux
++			targ_extra_emuls="shelf_linux shlelf_fd shelf_fd shlelf shelf"
+ 			targ_extra_libpath=shelf_linux ;;
+ sh64eb-*-linux*)	targ_emul=shelf32_linux
+ 			targ_extra_emuls="shlelf32_linux" ;;
+ sh64-*-linux*)		targ_emul=shlelf32_linux
+ 			targ_extra_emuls="shelf32_linux"
+ 			targ_extra_libpath=shelf32_linux ;;
+-sh*eb-*-linux*)		targ_emul=shelf_linux ;;
+-sh*-*-linux*)		targ_emul=shlelf_linux ;;
++sh*eb-*-linux*)		targ_emul=shelf_linux
++			targ_extra_emuls="shelf_fd shelf" ;;
++sh*-*-linux*)		targ_emul=shlelf_linux
++			targ_extra_emuls="shlelf_fd shlelf" ;;
+ sh5le-*-netbsd*)	targ_emul=shlelf32_nbsd
+ 			targ_extra_emuls="shelf32_nbsd shelf64_nbsd shlelf64_nbsd shelf_nbsd shlelf_nbsd" ;;
+ sh5-*-netbsd*)		targ_emul=shelf32_nbsd

patches/gcc-5.2.0/0001-musl.diff

@@ -598,7 +598,7 @@ diff --git a/gcc/config/sh/linux.h b/gcc/config/sh/linux.h
 index 0f5d614..4c167c6 100644
 --- a/gcc/config/sh/linux.h
 +++ b/gcc/config/sh/linux.h
-@@ -43,6 +43,28 @@ along with GCC; see the file COPYING3.  If not see
+@@ -43,6 +43,29 @@ along with GCC; see the file COPYING3.  If not see
  
  #define TARGET_ASM_FILE_END file_end_indicate_exec_stack
  
@@ -622,7 +622,8 @@ index 0f5d614..4c167c6 100644
 +
 +#undef MUSL_DYNAMIC_LINKER
 +#define MUSL_DYNAMIC_LINKER \
-+  "/lib/ld-musl-sh" MUSL_DYNAMIC_LINKER_E MUSL_DYNAMIC_LINKER_FP ".so.1"
++  "/lib/ld-musl-sh" MUSL_DYNAMIC_LINKER_E MUSL_DYNAMIC_LINKER_FP \
++  "%{mfdpic:-fdpic}.so.1"
 +
  #define GLIBC_DYNAMIC_LINKER "/lib/ld-linux.so.2"