Force the pre-C++11 ABI when compiling the parser library on Linux platforms.
Force the pre-C++11 ABI when compiling the parser library on Linux platforms.

Hopefully fixes a long-standing compatibility issue caused by the C++11 ABI switch on GCC5.

Fixes https://github.com/mono/CppSharp/issues/655.

ddobrev/CppSharp,zillemarco/CppSharp,u255436/CppSharp,zillemarco/CppSharp,mono/CppSharp,ddobrev/CppSharp,ktopouzi/CppSharp,mohtamohit/CppSharp,ktopouzi/CppSharp,zillemarco/CppSharp,u255436/CppSharp,u255436/CppSharp,ktopouzi/CppSharp,genuinelucifer/CppSharp,mohtamohit/CppSharp,mono/CppSharp,ktopouzi/CppSharp,zillemarco/CppSharp,genuinelucifer/CppSharp,inordertotest/CppSharp,mohtamohit/CppSharp,inordertotest/CppSharp,mono/CppSharp,mono/CppSharp,genuinelucifer/CppSharp,u255436/CppSharp,inordertotest/CppSharp,genuinelucifer/CppSharp,genuinelucifer/CppSharp,ddobrev/CppSharp,mohtamohit/CppSharp,ddobrev/CppSharp,ktopouzi/CppSharp,mono/CppSharp,inordertotest/CppSharp,u255436/CppSharp,zillemarco/CppSharp,inordertotest/CppSharp,mono/CppSharp,ddobrev/CppSharp,mohtamohit/CppSharp