Commit Message:

Clang and gcc are subtly different and it seems to be the cause of contrib build failures reported in
#31807 (e.g., when using gcc to link the final binary it results in a bunch of essential for gcc C++ symbols like __gxx_personality_v0).

The issue appear to be the order of the libraries when linking. gcc, when building statically linked binaries basically needs libstdc++ to be the last library or alsmot the last library in the command line. And clang does not appear to care about it much.

This change provides libstdc++ library in LIBS environment variabe which will put it in the right position when building the ICU library. This works well for both clang and gcc.

Additional Description:

It address the issue reported in #31807, though by itseld this change is not enough to make gcc builds work - a few more changes are needed.

Risk Level: Low
Testing: built with --config=gcc and --config=docker-gcc and checked that //contrib/language/filters/http/test:language_config_test pass after the change.
Docs Changes: N/A
Release Notes: N/A
Platform Specific Features: N/A

Request variables

Key	Value
ref	0f2c2a7
sha	03eb9a7
pr	37060
base-sha	522c94a
actor	@krinkinmu
message	[contrib][http language filter] Change position of libstdc++ library when linking ICU tools...
started	1731065941.83075
target-branch	main
trusted	false

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