[SBBreakpoint] Outline some functions to prevent to be exported.

They're hidden, so all they cause is a linker warning.

ld: warning: cannot export hidden symbol
lldb::SBBreakpointNameImpl::operator==(lldb::SBBreakpointNameImpl const&) from
tools/lldb/source/API/CMakeFiles/liblldb.dir/SBBreakpointName.cpp.o

llvm-svn: 320066