Restore buildability on rosa2016.1

Commit 6aceefa0 lost using CXXFLAGS / LDFLAGS when building gn.
Fix incorrect position of unset() (noted by alzim@, thanks to him)

ALT-allow-to-override-clang-through-env-variables.patch

@@ -3,6 +3,7 @@ From: Alexey Gladkov <legion@altlinux.org>
 Date: Mon, 27 Aug 2018 14:59:55 +0300
 Subject: [PATCH] ALT: allow to override clang through env variables
 
+[ mikhailnov@ROSA: added *FLAGS envs. ]
 ---
  build/toolchain/gcc_toolchain.gni | 7 +++++++
  1 file changed, 7 insertions(+)
@@ -11,7 +12,7 @@ diff --git a/build/toolchain/gcc_toolchain.gni b/build/toolchain/gcc_toolchain.g
 index 6e3c02444d0..bc6c6d705d3 100644
 --- a/build/toolchain/gcc_toolchain.gni
 +++ b/build/toolchain/gcc_toolchain.gni
-@@ -627,20 +627,27 @@ template("clang_toolchain") {
+@@ -627,20 +627,32 @@ template("clang_toolchain") {
  
    gcc_toolchain(target_name) {
      prefix = rebase_path("$clang_base_path/bin", root_build_dir)
@@ -28,6 +29,11 @@ index 6e3c02444d0..bc6c6d705d3 100644
 +    readelf = getenv("READELF")
 +    ar = getenv("AR")
 +    nm = getenv("NM")
++
++    extra_cflags = getenv("CFLAGS")
++    extra_cppflags = getenv("CPPFLAGS")
++    extra_cxxflags = getenv("CXXFLAGS")
++    extra_ldflags = getenv("LDFLAGS")
 +
      forward_variables_from(invoker,
                             [

chromium-browser-stable.spec

@@ -548,8 +548,8 @@ CXXFLAGS="-nostdinc++ \
           -I%{_includedir}/libstdc++-gcc10 \
           -I%{_includedir}/libstdc++-gcc10/%{_host} \
          " \
-unset LDFLAGS CXXFLAGS
 %{__python} tools/gn/bootstrap/bootstrap.py --gn-gen-args='%{gn_config}'
+unset LDFLAGS CXXFLAGS
 out/Release/gn gen --script-executable=%{__python} --args='%{gn_config}' out/Release
 
 pushd out/Release