When the `preserveWhitespaces` is not true, the template parser will
process the parsed AST nodes to remove excess whitespace. Since the
generated `goog.getMsg()` statements rely upon the AST nodes after
this whitespace is removed, the i18n extraction must make a second pass.
Previously this resulted in innacurrate source-spans for the i18n text and
placeholder nodes that were extracted in the second pass.
This commit fixes this by reusing the source-spans from the first pass
when extracting the nodes in the second pass.
Fixes#39671
PR Close#39717