Auto-handling of the gcc version through TC_GCC

[th0ma7]

Description

While working on a build issue with comcerto2k on DSM7 where it uses an older gcc version than other archs (ref. #5096), I thought of removing the manually provided TC_GCC to the benefit of automating it.

Checklist

• Build rule all-supported completed successfully
• New installation of package completed successfully
• Package upgrade completed successfully (Manually install the package again)
• Package functionality was tested
• Any needed documentation is updated/created

Type of change

• Bug fix
• New Package
• Package update
• Includes small framework changes
• This change requires a documentation update (e.g. Wiki)

[th0ma7]

@hgy59 if I recall you're the one that last played with this code. I came accros this and thought that would eliminate any remaining potential false-positives.

Note that I tried finding something similar for GLIBC but that ain't as easy as I thought. That may be for another time.

[ymartin59]

I wonder if it would be "enough" to retrieve information from gcc -dumpversion dynamically?

[th0ma7]

@ymartin59 its exactly that:

	  if [ "$${target}" = "cc" ] ; then \
	    gcc_version=`eval $$(echo $(WORK_DIR)/$(TC_TARGET)/bin/$(TC_PREFIX)$${source} -dumpversion)` ; \
	  fi ; \

[th0ma7]

@hgy59 and @ymartin59 this is ready for merge. I've rebased against master and recent changes on the toolchain & kernel. This really is a relatively trivial change that removes all TC_GCC in favor of calling gcc -dumpversion, removing both cruft in our configurations and false-positives.

Before merging a quick review from on of you would be appreciated.

[hgy59]

LGTM

was just wondering whether it would be possible to get the glibc version from the executables too.

(tried https://stackoverflow.com/questions/15134548/which-glibc-version-is-using-my-toolchain and https://stackoverflow.com/questions/9705660/check-glibc-version-for-a-particular-gcc-compiler but didn't find the matching version).

[th0ma7]

I also tried but failed miserably in doing so for GLIBC... perhaps in a subsequent PR.
Thnx for your review.