[vm/ffi] Verification of the generated program failed: '...' has no fileUri

[dcharkes]

The frontend transformations do not provide fileUrl and fileOffset for newly introduced members.

/==========================================================================================\
| fasta-linux:samples/ffi/samples_test is new and failed (CompileTimeError, expected Pass) |
\==========================================================================================/

--- Command "fasta" (took 12.000025s):
(cd /b/s/w/ir/ ; DART_CONFIGURATION=ReleaseX64 ./out/ReleaseX64/dart ./pkg/front_end/tool/_fasta/compile.dart --verify -o ./out/ReleaseX64/generated_compilations/fasta/samples_ffi_samples_test/out.dill --platform ./out/ReleaseX64/vm_platform_strong.dill --packages=./.packages ./samples/ffi/samples_test.dart )

exit code:
1

stdout:
samples/ffi/coordinate.dart: Error: Verification of the generated program failed:
'x' has no fileUri
samples/ffi/coordinate.dart: Error: Verification of the generated program failed:
'x' has no fileUri
samples/ffi/coordinate.dart: Error: Verification of the generated program failed:
'y' has no fileUri
samples/ffi/coordinate.dart: Error: Verification of the generated program failed:
'y' has no fileUri
samples/ffi/coordinate.dart: Error: Verification of the generated program failed:
'next' has no fileUri
samples/ffi/coordinate.dart: Error: Verification of the generated program failed:
'next' has no fileUri

--- Re-run this test:
python tools/test.py -n fasta-linux samples/ffi/samples_test

https://logs.chromium.org/logs/dart/buildbucket/cr-buildbucket.appspot.com/8898990163267264880/+/steps/test_results/0/logs/unapproved_new_test_failures__logs_/0

/cc @mkustermann