Whatever you did, it messed up the command line that g++ is invoked with:

g++ Sybase.def -o blib\arch\auto\DBD\Sybase\Sybase.xs.dll -mdll -s -L"
+C:\STRAWB~1\perl\lib\CORE" -L"C:\STRAWB~1\c\lib"-L"c:\SAP\OCS-16_0\dl
+l\" Sybase.o ...
[download]

Note how these escaped bckslashes and missing spaces in your addition are unlike the other -L stanzas.

A first step would be to make these identical to the other -L stanzas and add proper whitespace:

g++ Sybase.def -o blib\arch\auto\DBD\Sybase\Sybase.xs.dll -mdll -s -L"
+C:\STRAWB~1\perl\lib\CORE" -L"C:\STRAWB~1\c\lib" -L "c:\SAP\OCS-16_0\
+dll" Sybase.o
[download]

Also, there should be a way to pass the proper parameters to Makefile.PL from the command line instead of patching Makefile.PL.