workaround for clang-18 avx-512 problem

env/clang-17

@@ -0,0 +1,33 @@
+COMMON_FLAGS="-O2 -pipe -march=native -flto=thin"
+
+CFLAGS="${COMMON_FLAGS}"
+CXXFLAGS="${COMMON_FLAGS}"
+FCFLAGS="${COMMON_FLAGS}"
+FFLAGS="${COMMON_FLAGS}"
+
+CC="clang-17"
+CXX="clang++-17"
+
+AR="llvm-ar"
+AS="clang-17 -c"
+CPP="clang-cpp"
+NM="llvm-nm"
+STRIP="llvm-strip"
+RANLIB="llvm-ranlib"
+OBJCOPY="llvm-objcopy"
+STRINGS="llvm-strings"
+OBJDUMP="llvm-objdump"
+READELF="llvm-readelf"
+ADDR2LINE="llvm-addr2line"
+
+
+LD="ld.lld"
+
+LDFLAGS="-Wl,-O1 -Wl,--as-needed"
+
+LDFLAGS="${LDFLAGS} -rtlib=compiler-rt -unwindlib=libunwind"
+
+LDFLAGS="${LDFLAGS} -fuse-ld=lld -flto"
+
+
+USE="${USE} clang llvm-libunwind"