Validator: Create the newline indices lazily
Validator: Create the newline indices lazily

... since we rarely expect to see an error in the schema file.

Rolstenhouse/sarif-sdk,kschecht/sarif-sdk,kschecht/sarif-sdk,kschecht/sarif-sdk,kschecht/sarif-sdk,Rolstenhouse/sarif-sdk,kschecht/sarif-sdk,Rolstenhouse/sarif-sdk,kschecht/sarif-sdk,Rolstenhouse/sarif-sdk,Rolstenhouse/sarif-sdk,Rolstenhouse/sarif-sdk,Rolstenhouse/sarif-sdk,kschecht/sarif-sdk