Update GCC compiler driver to call ld directly for linking, not gcc/g++

[timpokorny]

Summary

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When configured to use GCC/G++ <cpptask> currently calls the gcc/g++ executable to both compile and link. This should be changed so that it calls ld directly to perform linking.

What I'm trying to do

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Pass linker arguments to ld without having to specify -Wl,

Work Breakdown

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<tbc>