thunderbird: fix build on loongson3 (and possibly others)

- (loongson3) Disable Clang due to missing ld.lld (linkage failure).
- (loongson3) Use the bfd linker.
- (loongosn3) Drop unsupported --disable-elf-hacks option.
- Sync LTO flag hack from Firefox to fix build, as some architectures, such as
  loongson3, has extra LTO flags starting with -flto (-flto-partition=none).
- Make wasi-sysroot sandbox optional.

app-web/thunderbird/autobuild/defines

@@ -11,7 +11,6 @@ PKGDES="Standalone mail and news reader from Mozilla"
 PKGBREAK="thunderbird-i18n<=38.5.0"
 PKGREP="thunderbird-i18n<=38.5.0"
 
-# FIXME: ld.lld of llvm 15 complains about "relocation R_MIPS_64 cannot be used against local symbol" in loongson3. Skip for now.
 USECLANG=1
 ABSPLITDBG=0
 
@@ -21,3 +20,6 @@ AB_FLAGS_PIE=0
 # FIXME: LLVM crashes.
 USECLANG__PPC64EL=0
 NOLTO__PPC64EL=1
+
+# FIXME: ld.lld is not available.
+USECLANG__LOONGSON3=0

app-web/thunderbird/autobuild/mozconfig

@@ -26,14 +26,10 @@ ac_add_options --allow-addon-sideload
 ac_add_options --with-google-location-service-api-keyfile="$SRCDIR"/autobuild/google-api-key
 ac_add_options --with-google-safebrowsing-api-keyfile="$SRCDIR"/autobuild/google-api-key
 
-# WASI.
-ac_add_options --with-wasi-sysroot=/usr/lib/wasm32-wasi/
-
 # Toolchain settings.
 ac_add_options --enable-optimize="-O2"
 ac_add_options --enable-release
 ac_add_options --disable-strip
-ac_add_options --enable-linker=lld
 ac_add_options --enable-hardening
 
 # Dependencies.

app-web/thunderbird/autobuild/prepare

@@ -1,6 +1,6 @@
-abinfo "Stripping LTO flags, let Firefox decide ..."
-export CFLAGS="${CFLAGS/\-flto/}"
-export CXXFLAGS="${CXXFLAGS/\-flto/}"
+abinfo "Stripping LTO flags, let Thunderbird decide ..."
+export CFLAGS="${CFLAGS/\-flto=$ABTHREADS/}"
+export CXXFLAGS="${CXXFLAGS/\-flto=$ABTHREADS/}"
 export LDFLAGS="${LDFLAGS/\-flto/}"
 
 abinfo "Installing mozconfig ..."
@@ -18,15 +18,30 @@ if ab_match_arch loongson3; then
     echo "ac_add_options --disable-jit" >> "$SRCDIR"/mozconfig
 fi
 
-# FIXME: --disable-elf-hack is not available for ppc64el.
-if ! ab_match_arch ppc64el; then
+# FIXME: --disable-elf-hack is not available for loongson3, ppc64el.
+if ! ab_match_arch loongson3 && \
+   ! ab_match_arch ppc64el; then
     abinfo "Setting --disable-elf-hack ..."
     echo "ac_add_options --disable-elf-hack" \
-        >> "$SRCDIR"/autobuild/mozconfig
+        >> "$SRCDIR"/mozconfig
+fi
 
+if ! ab_match_arch ppc64el; then
     abinfo "Use the gold linker ..."
     echo "ac_add_options --enable-linker=gold" \
-        >> "$SRCDIR"/autobuild/mozconfig
+        >> "$SRCDIR"/mozconfig
+fi
+
+if ! ab_match_arch loongson3; then
+    echo "ac_add_options --enable-linker=lld" \
+        >> "$SRCDIR"/mozconfig
+    echo "ac_add_options --with-wasi-sysroot=/usr/lib/wasm32-wasi/" \
+        >> "$SRCDIR"/mozconfig
+else
+    echo "ac_add_options --enable-linker=bfd" \
+        >> "$SRCDIR"/mozconfig
+    echo "ac_add_options --without-wasm-sandboxed-libraries" \
+        >> "$SRCDIR"/mozconfig
 fi
 
 abinfo "Declaring $SHELL as /bin/bash ..."

app-web/thunderbird/spec

@@ -1,5 +1,5 @@
 VER=115.2.2
-REL=1
+REL=2
 CHKUPDATE="anitya::id=4967"
 SRCS="https://archive.mozilla.org/pub/thunderbird/releases/$VER/source/thunderbird-$VER.source.tar.xz \
       file::rename=af.xpi::http://ftp.mozilla.org/pub/thunderbird/releases/$VER/linux-x86_64/xpi/af.xpi \