Clang: patch to link with -lc and -lposix

Link with the libc and posix entrypoint library unless the -noposix flag
is passed. This allows the Genode Clang to be dropped into legacy build
systems.

Update the native packages using the Clang stdenv to pass -noposix.

overlay/llvm-8/clang/genode.patch

@@ -1,3 +1,15 @@
+diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
+index d02d9744d78..b57a7cb0507 100644
+--- a/include/clang/Driver/Options.td
++++ b/include/clang/Driver/Options.td
+@@ -2452,6 +2452,7 @@ def nolibc : Flag<["-"], "nolibc">;
+ def nomultidefs : Flag<["-"], "nomultidefs">;
+ def nopie : Flag<["-"], "nopie">;
+ def no_pie : Flag<["-"], "no-pie">, Alias<nopie>;
++def noposix : Flag<["-"], "noposix">;
+ def noprebind : Flag<["-"], "noprebind">;
+ def noseglinkedit : Flag<["-"], "noseglinkedit">;
+ def nostartfiles : Flag<["-"], "nostartfiles">;
 diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
 index 3c139d72479..89d6df3f5b4 100644
 --- a/lib/Basic/Targets.cpp
@@ -109,10 +121,10 @@ index 1a46073aaa3..72b6f7389a3 100644
          StringRef S = A->getValue();
 diff --git a/lib/Driver/ToolChains/Genode.cpp b/lib/Driver/ToolChains/Genode.cpp
 new file mode 100644
-index 00000000000..9103ce2a5ee
+index 00000000000..91cb8362a14
 --- /dev/null
 +++ b/lib/Driver/ToolChains/Genode.cpp
-@@ -0,0 +1,133 @@
+@@ -0,0 +1,138 @@
 +//===--- Genode.cpp - Genode ToolChain Implementations ----------*- C++ -*-===//
 +//
 +//                     The LLVM Compiler Infrastructure
@@ -206,6 +218,11 @@ index 00000000000..9103ce2a5ee
 +
 +  AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
 +
++  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs, options::OPT_noposix)) {
++    CmdArgs.push_back("-lc");
++    CmdArgs.push_back("-lposix");
++  }
++
 +  const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
 +  C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
 +}

packages/block_router/default.nix

@@ -10,8 +10,8 @@ stdenv.mkDerivation rec {
 
   src = fetchgit {
     url = "https://git.sr.ht/~ehmry/block_router";
-    rev = "v" + version;
+    rev = "d229379abd16d6b19872b83772da81a2473f18ae";
-    sha256 = "0vw3s4q3rp5dp1i93sq0cybfssh3gbqgyqg6k69781pjda7mzn54";
+    sha256 = "1wrz7r72psnxfaaj2gjp5zxy8h4k8ahbyjp8y70ghr9rm1hsdhj4";
   };
 
   installPhase = "install -Dm755 {.,$out}/block_router";

packages/nic_bus/default.nix

@@ -7,8 +7,8 @@ stdenv.mkDerivation rec {
 
   src = fetchgit {
     url = "https://git.sr.ht/~ehmry/nic_bus";
-    rev = "v" + version;
+    rev = "e4e7c5f4af7d6129f64afb019045c40508a619ee";
-    sha256 = "DrgZHkUEjkHmSfOqSetGqU/nLl8OqNM0zaJjOout5VY=";
+    sha256 = "0hxzdkl1w47gha395bx8ykv8ic62chs75ccyyqq841pwghqxscj4";
   };
 
   nativeBuildInputs = [ tup ];

packages/sotest-producer/default.nix

@@ -10,8 +10,8 @@ stdenv.mkDerivation rec {
 
   src = fetchgit {
     url = "https://git.sr.ht/~ehmry/genode-sotest-producer";
-    rev = "v" + version;
+    rev = "eed74df5977b01809893efaa84e7ad6d207423d2";
-    sha256 = "01qy86khkihj8jgvgc92w4bb3kpf640g1l2m5h5ym7s03viqinkr";
+    sha256 = "1cf08jk2y6advlk9hczzklc220195fj3ybjvd16y8v1sfpfg84lx";
   };
 
   installPhase = "install -Dm755 {.,$out/bin}/sotest-harness";