Fix PDB/func-symbols.test for Arm/Windows

PDB/func-symbols.test was orignally written for 32bit x86, keeping in
mind cdecl and stdcall calling conventions which does name mangling for
example like adding "_" underscore before function name.
This is only x86 specific but purpose of pointers.test is NOT to test
calling convention.
I have made a minor change to make this test pass on Windows/Arm.