asserts don't print failed condition if sources are not present in kernel file #34586
Description
When dart vm runs against kernel file without source code embedded in it, failed asserts report null instead of original dart condition:
'\'file:///$FH/flutter/packages/flutter/test/foundation/error_reporting_test.dart\': Failed assertion: line 12 pos 12: \'null\'',
The penalty of having source code present just to have asserts reporting correct condition seems to be too high: for flutter tests (package/flutter) average kernel file with the source is 16M vs 6M without source. Test execution time when running against kernel files without source code drops by ~25% (from 2m50s to 2m07s).
It seems reasonable for assert in Kernel AST to capture source text condition in the kernel file itself instead of capturing just token positions.