Enable new dtags in a way that works with binutils 2.30.

In 3027bca, binutils was upgraded from 2.28.1 to 2.30. However, in 2.30,
the ldmain.c file within binutils, which the nixpkgs new-dtags.patch
file is meant to modify, was changed in such a way that the patch no
longer works. As a result, the new dtags are not actually enabled, and
binaries are built with RPATH set instead of RUNPATH, thereby preventing
LD_LIBRARY_PATH from overriding this built-in path. This change corrects
this. The patch file is no longer necessary because binutils's ldmain.c
now sets link_info.new_dtags based on the configuration flags.

This was probably not noticed immediately because, when the derivation
is built with nix-build, the fixupPhase runs patchelf --shrink-rpath.
patchelf converts any RPATH in the binary into RUNPATH (unless
--force-rpath is specified).  Of course, if the binary is built without
nix-build (such as in a nix-shell), this never occurs, and any RPATH in
the binary is left in place.

pkgs/development/tools/misc/binutils/default.nix

@@ -26,11 +26,6 @@ stdenv.mkDerivation rec {
   });
 
   patches = [
-    # Turn on --enable-new-dtags by default to make the linker set
-    # RUNPATH instead of RPATH on binaries.  This is important because
-    # RUNPATH can be overriden using LD_LIBRARY_PATH at runtime.
-    ./new-dtags.patch
-
     # Since binutils 2.22, DT_NEEDED flags aren't copied for dynamic outputs.
     # That requires upstream changes for things to work. So we can patch it to
     # get the old behaviour by now.
@@ -117,6 +112,11 @@ stdenv.mkDerivation rec {
     "--enable-deterministic-archives"
     "--disable-werror"
     "--enable-fix-loongson2f-nop"
+
+    # Turn on --enable-new-dtags by default to make the linker set
+    # RUNPATH instead of RPATH on binaries.  This is important because
+    # RUNPATH can be overriden using LD_LIBRARY_PATH at runtime.
+    "--enable-new-dtags"
   ] ++ optionals gold [ "--enable-gold" "--enable-plugins" ];
 
   doCheck = false; # fails

pkgs/development/tools/misc/binutils/new-dtags.patch

@@ -1,10 +0,0 @@
---- binutils/ld/ldmain.c
-+++ binutils/ld/ldmain.c
-@@ -296,6 +296,7 @@ main (int argc, char **argv)
-
-   link_info.allow_undefined_version = TRUE;
-   link_info.keep_memory = TRUE;
-+  link_info.new_dtags = TRUE;
-   link_info.combreloc = TRUE;
-   link_info.strip_discarded = TRUE;
-   link_info.callbacks = &link_callbacks;