qt5: enable JS and WebKit for ARC

This patch adds support of ARC architecture in Qt's JS core and Webkit.
The change itself is quite straight-forward:

 1. Enable JS core for ARC
 2. Make sure so-called "large memory model" is used,
    i.e. relocations with long jumps are being generated for global
    symbols, as otherwise insanely huge libqt5webkit.so fails to link
    because some symbols might be more than 32 MiB away from each other.
 3. Make the original WebKit build system aware of yet another CPU
    architecture with explicitly disabled JIT in JS core for ARC.

Obviously, this one depends on [1].

[1] https://patchwork.ozlabs.org/project/buildroot/patch/20220221140628.2295-1-abrodkin@synopsys.com/



Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>