qtpdf: Fix build with clang

use GNU runtime when building native tools like gn
when using native clang compiler

Fixes
| FAILED: gn
| /mnt/b/yoe/master/build/tmp/work/core2-64-yoe-linux/qtpdf/5.15.8+gitAUTOINC+73e76f9e86_48a205f9e0-r0/recipe-sysroot-native/usr/bin/clang++ -O3 -fdata-sections -ffunction-sections -Wl,--gc-sections -Wl,-stri
p-all -Wl,--as-needed -pthread -o gn -Wl,--start-group tools/gn/gn_main.o base.a gn_lib.a -Wl,--end-group -ldl
| /mnt/b/yoe/master/build/tmp/hosttools/ld: cannot find /usr/lib/clang/14.0.0/lib/linux/libclang_rt.builtins-x86_64.a: No such file or directory

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

recipes-qt/qt5/qtpdf/native-clang.patch

@@ -0,0 +1,19 @@
+Fix building with clang from meta-clang
+
+Clang defaults to llvm runtime and this patch is needed
+for building the host tools, since its using native runtime
+
+Upstream-Status: Inappropriate [OE-Specific]
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+
+--- a/src/buildtools/gn.pro
++++ b/src/buildtools/gn.pro
+@@ -20,7 +20,7 @@ build_pass|!debug_and_release {
+ 
+             gn_gen_args = --no-last-commit-position --out-path $$out_path \
+                           --cc \"$$which($$CC_host)\" --cxx \"$$which($$CXX_host)\" \
+-                          --ld \"$$which($$CXX_host)\" --ar \"$$which(ar)\" \
++                          --ld \"$$which($$CXX_host) -rtlib=libgcc -unwindlib=libgcc\" --ar \"$$which(ar)\" \
+                           --no-static-libstdc++
+ 
+             msvc:!clang_cl: gn_gen_args += --use-lto

recipes-qt/qt5/qtpdf_git.bb

@@ -151,6 +151,8 @@ SRC_URI:append:libc-musl = "\
     file://0005-mkspecs-Allow-builds-with-libc-glibc.patch \
 "
 
+SRC_URI:append:runtime-llvm = " file://native-clang.patch "
+
 SRCREV_qtwebengine = "73e76f9e86b3fded45be6b232bdebe75e7136e4a"
 SRCREV_chromium = "48a205f9e054b5cc3e67df2e25382da9460c0015"
 SRCREV = "${SRCREV_qtwebengine}"