[clang] Correct -frewrite-includes generation of line control directives with mixed EOL forms.

Previously, if a header file and a source file used different end of line
(EOL) forms, preprocessed output generated with the -frewrite-includes option
would, in some cases, generate line control directives with the wrong line
number due to an error in how source file lines were counted.

Fixes https://github.com/llvm/llvm-project/issues/59736

Reviewed By: cor3ntin

Differential Revision: https://reviews.llvm.org/D140984