re PR libstdc++/64438 (Removing string-conversion requirement causes libstdc++-v3...

re PR libstdc++/64438 (Removing string-conversion requirement causes libstdc++-v3 fails on AArch64.)

	PR libstdc++/64438
	* testsuite/21_strings/basic_string/numeric_conversions/char/dr1261.cc:
	Revert removal of dg-require-string-conversions.
	* testsuite/21_strings/basic_string/numeric_conversions/char/stod.cc:
	Likewise.
	* testsuite/21_strings/basic_string/numeric_conversions/char/stof.cc:
	Likewise.
	* testsuite/21_strings/basic_string/numeric_conversions/char/stoi.cc:
	Likewise.
	* testsuite/21_strings/basic_string/numeric_conversions/char/stol.cc:
	Likewise.
	* testsuite/21_strings/basic_string/numeric_conversions/char/stold.cc:
	Likewise.
	* testsuite/21_strings/basic_string/numeric_conversions/char/stoll.cc:
	Likewise.
	* testsuite/21_strings/basic_string/numeric_conversions/char/stoul.cc:
	Likewise.
	* testsuite/21_strings/basic_string/numeric_conversions/char/
	stoull.cc: Likewise.
	* testsuite/21_strings/basic_string/numeric_conversions/char/
	to_string.cc: Likewise.

From-SVN: r219146