This test migrates source-mapping tests to the new compliance test framework.
The original tests are found in the file at:
`packages/compiler-cli/test/ngtsc/template_mapping_spec.ts`.
These new tests also check the mappings resulting from partial compilation
followed by linking, after flattening the pair of source-maps that each
process generates.
Note that there are some differences between the mappings for full compile
and linked compile modes, due to how TypeScript and Babel use source-span
information on AST nodes. To accommodate this, there are two expectation
files for most of these source files.
PR Close#39939