add support for missing c++11 functions to newlib Due to a few missing double long complex functions, newlib fail's configure's c99 tests. With _GLIBCXX_USE_C99 unset, a variety of C++11 functions are lost, including to_string and snprintf. This modifies configure to not depend on the results of the complex test. This change is safe since code that attempts to use these missing complex functions will still fail to compile.
add support for missing c++11 functions to newlib
Due to a few missing double long complex functions, newlib fail's configure's c99 tests. With _GLIBCXX_USE_C99 unset, a variety of C++11 functions are lost, including to_string and snprintf. This modifies configure to not depend on the results of the complex test. This change is safe since code that attempts to use these missing complex functions will still fail to compile.

manuelafm/riscv-gnu-toolchain,manuelafm/riscv-gnu-toolchain,manuelafm/riscv-gnu-toolchain