gdb: allow nios2, workaround a riscv issue

package/gdb/Makefile

@@ -14,7 +14,7 @@ PKG_DEPENDS:=		libncurses zlib libexpat libthread-db
 PKG_BUILDDEP:=		ncurses readline expat zlib
 PKG_NEEDS:=		c++
 
-PKG_ARCH_DEPENDS:=	!arc !cris !avr32 !nios2 !microblaze
+PKG_ARCH_DEPENDS:=	!arc !cris !avr32 !microblaze
 
 include ${ADK_TOPDIR}/mk/package.mk
 

package/gdb/patches/patch-gdb_configure

@@ -1,6 +1,6 @@
---- gdb-8.0.orig/gdb/configure	2017-06-04 17:54:54.000000000 +0200
-+++ gdb-8.0/gdb/configure	2017-06-20 22:54:16.961589341 +0200
-@@ -14547,93 +14547,6 @@ $as_echo "$gdb_cv_bigtoc" >&6; }
+--- gdb-8.3.1.orig/gdb/configure	2019-09-21 00:04:41.000000000 +0200
++++ gdb-8.3.1/gdb/configure	2019-10-16 12:08:42.152038996 +0200
+@@ -15064,93 +15064,6 @@ $as_echo "$gdb_cv_bigtoc" >&6; }
    ;;
  esac
  

package/gdb/patches/patch-gdb_nat_ppc-linux_h

@@ -1,8 +1,8 @@
---- gdb-7.11.orig/gdb/nat/ppc-linux.h	2016-02-10 04:19:39.000000000 +0100
-+++ gdb-7.11/gdb/nat/ppc-linux.h	2016-04-24 21:19:39.351474402 +0200
+--- gdb-8.3.1.orig/gdb/nat/ppc-linux.h	2019-09-21 00:04:41.000000000 +0200
++++ gdb-8.3.1/gdb/nat/ppc-linux.h	2019-10-16 12:08:42.156039004 +0200
 @@ -18,7 +18,9 @@
- #ifndef PPC_LINUX_H
- #define PPC_LINUX_H 1
+ #ifndef NAT_PPC_LINUX_H
+ #define NAT_PPC_LINUX_H
  
 +#define pt_regs uapi_pt_regs
  #include <asm/ptrace.h>

package/gdb/patches/patch-gdb_riscv-tdep_c

@@ -0,0 +1,12 @@
+--- gdb-8.3.1.orig/gdb/riscv-tdep.c	2019-09-21 00:04:41.000000000 +0200
++++ gdb-8.3.1/gdb/riscv-tdep.c	2019-10-16 12:18:34.569267544 +0200
+@@ -3131,9 +3131,6 @@ riscv_gdbarch_init (struct gdbarch_info
+   /* We do support running binaries compiled for 32-bit float on targets
+      with 64-bit float, so we only complain if the binary requires more
+      than the target has available.  */
+-  if (abi_features.flen > features.flen)
+-    error (_("bfd requires flen %d, but target has flen %d"),
+-            abi_features.flen, features.flen);
+ 
+   /* If the ABI_FEATURES xlen is 0 then this indicates we got no useful abi
+      features from the INFO object.  In this case we assume that the xlen