feat: warn when using --unstable, prefer granular flags (#21452)

This commit deprecates "--unstable" flag. 

When "--unstable" flag is encountered a warning like this is printed:
```
The `--unstable` flag is deprecated, use granular `--unstable-*` flags instead.
Learn more at: https://docs.deno.com/runtime/manual/tools/unstable_flags
```
When "--unstable" flag is used and an unstable API is called an
additional warning like this is printed for each API call:
```
The `Deno.dlopen` API was used with `--unstable` flag. The `--unstable` flag is deprecated, use granular `--unstable-ffi` instead. 
Learn more at: https://docs.deno.com/runtime/manual/tools/unstable_flags
```
When no "--unstable-*" flag is provided and an unstable API is called
following
warning is issued before exiting:
```
Unstable API 'Deno.dlopen'. The `--unstable-ffi` flag must be provided.
```

---------

Signed-off-by: Divy Srivastava <dj.srivastava23@gmail.com>
Signed-off-by: Bartek Iwańczuk <biwanczuk@gmail.com>
Co-authored-by: Divy Srivastava <dj.srivastava23@gmail.com>
Co-authored-by: Asher Gomez <ashersaupingomez@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/cli/tests/integration/doc_tests.rs b/cli/tests/integration/doc_tests.rs
index 73a112261..62fd2a5b4 100644
--- a/cli/tests/integration/doc_tests.rs
+++ b/cli/tests/integration/doc_tests.rs
@@ -28,7 +28,7 @@ fn deno_doc() {
 }
 
 itest!(deno_doc_import_map {
-  args: "doc --unstable --import-map=doc/import_map.json doc/use_import_map.js",
+  args: "doc --import-map=doc/import_map.json doc/use_import_map.js",
   output: "doc/use_import_map.out",
 });