rustc: fix build with unbundled jemalloc and llvm on darwin

jemalloc with stripped prefix would cause segfaults in free:
NixOS#49557 (comment)

This commit has been adjusted from the one on master to only carry the
relevant changes (the new optional `stripPrefix`) flag while still
keeping the other flags that were removed on master since they are no
loner supported by the version used there.

(cherry picked from commit 973eca7)

pkgs/development/compilers/rust/rustc.nix

@@ -20,6 +20,8 @@ let
 
   llvmShared = llvm.override { enableSharedLibraries = true; };
 
+  prefixedJemalloc = jemalloc.override { stripPrefix = false; };
+
   target = builtins.replaceStrings [" "] [","] (builtins.toString targets);
 in
 

pkgs/development/libraries/jemalloc/common.nix

@@ -1,6 +1,13 @@
-{ stdenv, fetchurl, version, sha256, ... }@args:
+{ version, sha256 }:
+{ stdenv, fetchurl,
+# By default, jemalloc puts a je_ prefix onto all its symbols on OSX, which
+# then stops downstream builds (mariadb in particular) from detecting it. This
+# option should remove the prefix and give us a working jemalloc.
+# Causes segfaults with some software (ex. rustc), but defaults to true for backward
+# compatibility. Ignored on non OSX.
+stripPrefix ? true }:
 
-stdenv.mkDerivation (rec {
+stdenv.mkDerivation rec {
   name = "jemalloc-${version}";
   inherit version;
 
@@ -9,10 +16,7 @@ stdenv.mkDerivation (rec {
     inherit sha256;
   };
 
-  # By default, jemalloc puts a je_ prefix onto all its symbols on OSX, which
-  # then stops downstream builds (mariadb in particular) from detecting it. This
-  # option should remove the prefix and give us a working jemalloc.
-  configureFlags = stdenv.lib.optional stdenv.isDarwin "--with-jemalloc-prefix="
+  configureFlags = stdenv.lib.optional (stdenv.isDarwin && stripPrefix)  "--with-jemalloc-prefix="
                    # jemalloc is unable to correctly detect transparent hugepage support on
                    # ARM (https://github.com/jemalloc/jemalloc/issues/526), and the default
                    # kernel ARMv6/7 kernel does not enable it, so we explicitly disable support
@@ -32,4 +36,4 @@ stdenv.mkDerivation (rec {
     platforms = platforms.all;
     maintainers = with maintainers; [ wkennington ];
   };
-} // (builtins.removeAttrs args [ "stdenv" "fetchurl" "version" "sha256" ]))
+}

pkgs/development/libraries/jemalloc/default.nix

@@ -1,10 +1,4 @@
-{ stdenv, fetchurl, fetchpatch }:
 import ./common.nix {
-  inherit stdenv fetchurl;
-  version = "5.0.1";
-  sha256 = "4814781d395b0ef093b21a08e8e6e0bd3dab8762f9935bbfb71679b0dea7c3e9";
-  patches = stdenv.lib.optional stdenv.isAarch64 (fetchpatch {
-    url = "https://patch-diff.githubusercontent.com/raw/jemalloc/jemalloc/pull/1035.patch";
-    sha256 = "02y0q3dp253bipxv4r954nqipbjbj92p6ww9bx5bk3d8pa81wkqq";
-  });
+  version = "5.1.0";
+  sha256 = "0s3jpcyhzia8d4k0xyc67is78kg416p9yc3c2f9w6fhhqqffd5jk";
 }

pkgs/development/libraries/jemalloc/jemalloc450.nix

@@ -1,6 +1,4 @@
-{ stdenv, fetchurl }:
 import ./common.nix {
-  inherit stdenv fetchurl;
   version = "4.5.0";
   sha256 = "10373xhpc10pgmai9fkc1z0rs029qlcb3c0qfnvkbwdlcibdh2cl";
-}
+}