nodejs: support long directory names for ${B} / ${S}

Part of the NodeJS build builds V8, which at some stage tries to call
ar with all objects with *absolute* paths (and printf the command line
first).

This will fail if the build path is too long:
    make[1]: execvp: printf: Argument list too long
when trying to create Release/obj.target/deps/v8/gypfiles/libv8_base.a
via below gyp-generated out/Makefile rule:
    cmd_alink_thin = rm -f $@ && $(AR.$(TOOLSET)) crsT $@ $(filter %.o,$^)
i.e. something like
    printf rm -f Release/obj.target/deps/v8/gypfiles/libv8_base.a && arm-poky-linux-musleabi-gcc-ar crsT Release/obj.target/deps/v8/gypfiles/libv8_base.a ...

The above failure happened on a build-directory S with 204 characters
on a Jenkins machine.

While one could probably increase the ulimit on that specific machine,
that would be a pretty specific build machine fix which would need to
be applied everywhere, or switch to non-verbose builds / compilation,
but fortunately we can change all object references to be relative to
the build directory itself by setting the builddir_name make variable
and thus avoid the other two possible work-arounds.

Signed-off-by: André Draszik <git@andred.net>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-devtools/nodejs/nodejs_10.17.0.bb

@@ -69,6 +69,8 @@ EXTRA_OEMAKE = "\
     CXXFLAGS.host='${CPPFLAGS} ${CXXFLAGS}' \
     LDFLAGS.host='${LDFLAGS}' \
     AR.host='${AR}' \
+    \
+    builddir_name=./ \
 "
 
 python do_unpack() {