libcxx: add linker scripts for libc++.a to ensure libc++abi.a is properly linked

pkgs/development/compilers/llvm/4/libc++/default.nix

@@ -44,6 +44,11 @@ stdenv.mkDerivation rec {
 
   linkCxxAbi = stdenv.isLinux;
 
+  postInstall = ''
+    mv $out/lib/libc++.a $out/lib/libc++_static.a
+    cp ${./libc++.a} $out/lib/libc++.a
+  '';
+
   setupHooks = [
     ../../../../../build-support/setup-hooks/role.bash
     ./setup-hook.sh

pkgs/development/compilers/llvm/4/libc++/libc++.a

@@ -0,0 +1 @@
+INPUT(-lc++_static -lc++abi)

pkgs/development/compilers/llvm/5/libc++/default.nix

@@ -38,6 +38,11 @@ stdenv.mkDerivation rec {
 
   linkCxxAbi = stdenv.isLinux;
 
+  postInstall = ''
+    mv $out/lib/libc++.a $out/lib/libc++_static.a
+    cp ${./libc++.a} $out/lib/libc++.a
+  '';
+
   setupHooks = [
     ../../../../../build-support/setup-hooks/role.bash
     ./setup-hook.sh

pkgs/development/compilers/llvm/5/libc++/libc++.a

@@ -0,0 +1 @@
+INPUT(-lc++_static -lc++abi)

pkgs/development/compilers/llvm/6/libc++/default.nix

@@ -38,6 +38,11 @@ stdenv.mkDerivation rec {
 
   linkCxxAbi = stdenv.isLinux;
 
+  postInstall = ''
+    mv $out/lib/libc++.a $out/lib/libc++_static.a
+    cp ${./libc++.a} $out/lib/libc++.a
+  '';
+
   setupHooks = [
     ../../../../../build-support/setup-hooks/role.bash
     ./setup-hook.sh

pkgs/development/compilers/llvm/6/libc++/libc++.a

@@ -0,0 +1 @@
+INPUT(-lc++_static -lc++abi)

pkgs/development/compilers/llvm/7/libc++/default.nix

@@ -36,6 +36,11 @@ stdenv.mkDerivation rec {
 
   linkCxxAbi = stdenv.isLinux;
 
+  postInstall = ''
+    mv $out/lib/libc++.a $out/lib/libc++_static.a
+    cp ${./libc++.a} $out/lib/libc++.a
+  '';
+
   setupHooks = [
     ../../../../../build-support/setup-hooks/role.bash
     ./setup-hook.sh

pkgs/development/compilers/llvm/7/libc++/libc++.a

@@ -0,0 +1 @@
+INPUT(-lc++_static -lc++abi)