dxvk: Build fails with winegcc built by clang.

When building dxvk with a copy of winegcc which has been built by clang and using the build-wine32.txt or build-wine64.txt cross files the build will fail because only gcc supports --no-gnu-unique.

I am not sure if this flag is important to keep or how to work around this using meson…

I am building dxvk with this command line.

meson \
    --prefix=/usr \
    --libdir=share/dxvk/x32 \
    --cross-file=build-wine32.txt \
    -Dstrip=true \
    -Db_ndebug=true \
    -Dbuildtype=plain \
    build32

System information

• Wine version: 4.15
• DXVK version: 1.3.3
• meson version: 0.51.2
• clang version: 8.0.1

Log files

The Meson build system
Version: 0.51.2
Source dir: /tmp/SBo/dxvk-1.3.3
Build dir: /tmp/SBo/dxvk-1.3.3/build32
Build type: cross build
Project name: dxvk
Project version: v1.3.3
Appending CFLAGS from environment: '-O2 -fPIC'
C compiler for the build machine: clang (clang 8.0.1 "clang version 8.0.1 (tags/RELEASE_801/final)")
Appending CXXFLAGS from environment: '-O2 -fPIC'
C++ compiler for the build machine: clang++ (clang 8.0.1 "clang version 8.0.1 (tags/RELEASE_801/final)")
C compiler for the host machine: winegcc (clang 8.0.1 "clang version 8.0.1 (tags/RELEASE_801/final)")

meson.build:1:0: ERROR: Compiler wineg++ can not compile programs.

A full log can be found at /tmp/SBo/dxvk-1.3.3/build32/meson-logs/meson-log.txt

• meson-log.txt: meson-log.txt

clang-8: error: unsupported option '--no-gnu-unique'
winegcc: clang++ failed