nodejs: Fix build with clang for x86 target

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

meta-oe/recipes-devtools/nodejs/nodejs/libatomic.patch

@@ -0,0 +1,21 @@
+Link mksnapshot with libatomic on x86
+
+Clang-12 on x86 emits atomic builtins
+
+Fixes
+| module-compiler.cc:(.text._ZN2v88internal4wasm12_GLOBAL__N_123ExecuteCompilationUnitsERKSt10shared_ptrINS2_22BackgroundCompileTokenEEPNS0_8CountersEiNS2_19CompileBaselineOnlyE+0x558): un
+defined reference to `__atomic_load'
+
+Upstream-Status: Pending
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+
+--- a/tools/v8_gypfiles/v8.gyp
++++ b/tools/v8_gypfiles/v8.gyp
+@@ -1336,6 +1336,7 @@
+     {
+       'target_name': 'mksnapshot',
+       'type': 'executable',
++      'libraries': [ '-latomic' ],
+       'dependencies': [
+         'v8_base_without_compiler',
+         'v8_compiler_for_mksnapshot',

meta-oe/recipes-devtools/nodejs/nodejs_14.16.1.bb

@@ -27,6 +27,9 @@ SRC_URI = "http://nodejs.org/dist/v${PV}/node-v${PV}.tar.xz \
 SRC_URI_append_class-target = " \
            file://0002-Using-native-binaries.patch \
            "
+SRC_URI_append_toolchain-clang_x86 = " \
+           file://libatomic.patch \
+           "
 SRC_URI[sha256sum] = "e44adbbed6756c2c1a01258383e9f00df30c147b36e438f6369b5ef1069abac3"
 
 S = "${WORKDIR}/node-v${PV}"
@@ -123,6 +126,8 @@ python do_create_v8_qemu_wrapper () {
 do_create_v8_qemu_wrapper[dirs] = "${B}"
 addtask create_v8_qemu_wrapper after do_configure before do_compile
 
+LDFLAGS_append_x86 = " -latomic"
+
 # Node is way too cool to use proper autotools, so we install two wrappers to forcefully inject proper arch cflags to workaround gypi
 do_configure () {
     export LD="${CXX}"