feat(tvix/glue/derivationStrict): support __structuredAttrs

This adds support to handle the __structuredAttrs argument, which can be
passed to builtins.derivationStrict.

If __structuredAttrs is passed, and set to true, most of the arguments
passed to builtins.derivationStrict are not simply coerced to a string
and passed down to "environments", but instead kept in a more structured
fashion.

Inside ATerm, which is what's relevant as far as path calculation is
concerned, a virtual `__json` environment variable is present,
containing these structured values.

Inside Builds, these structured values are not made available as an
environment variable, but a JSON file (and source-able bash script).

This will need to be respected once we start emitting BuildRequests,
and for that we can probably just parse the `__json` key in
Derivation.environment again - or keep this additionally in
non-serialized form around during Evaluation.
No matter what, this is left for a followup CL.

The existing handle_derivation_parameters and populate_outputs helper
function were removed, as __structuredAttrs causes quite a change
in behaviour, and so handling both in the same place makes it more
readable.

There's some open questions w.r.t. string contexts for structured attrs
itself. A TODO is left for this, but at least path calculation for
individual structured attrs derivations are correct now.

Part of b/366.

Change-Id: Ic293822266ced6f8c4826d8ef0d2e098a4adccaa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10604
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>

tvix/Cargo.lock

@@ -307,9 +307,9 @@ dependencies = [
 
 [[package]]
 name = "bstr"
-version = "1.6.0"
+version = "1.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6798148dccfbff0fae41c7574d2fa8f1ef3492fba0face179de5d8d447d67b05"
+checksum = "c48f0051a4b4c5e0b6d365cd04af53aeaa209e3cc15ec2cdb69e73cc87fbd0dc"
 dependencies = [
  "memchr",
  "regex-automata",
@@ -1458,9 +1458,9 @@ checksum = "b87248edafb776e59e6ee64a79086f65890d3510f2c656c000bf2a7e8a0aea40"
 
 [[package]]
 name = "memchr"
-version = "2.5.0"
+version = "2.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
+checksum = "523dc4f511e55ab87b694dc30d0f820d60906ef06413f93d4d7a1385599cc149"
 
 [[package]]
 name = "memoffset"
@@ -2206,9 +2206,9 @@ dependencies = [
 
 [[package]]
 name = "regex-automata"
-version = "0.3.4"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b7b6d6190b7594385f61bd3911cd1be99dfddcfc365a4160cc2ab5bff4aed294"
+checksum = "5f804c7828047e88b2d32e2d7fe5a105da8ee3264f01902f796c8e067dc2483f"
 
 [[package]]
 name = "regex-syntax"
@@ -2498,18 +2498,18 @@ checksum = "836fa6a3e1e547f9a2c4040802ec865b5d85f4014efe00555d7090a3dcaa1090"
 
 [[package]]
 name = "serde"
-version = "1.0.162"
+version = "1.0.195"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "71b2f6e1ab5c2b98c05f0f35b236b22e8df7ead6ffbf51d7808da7f8817e7ab6"
+checksum = "63261df402c67811e9ac6def069e4786148c4563f4b50fd4bf30aa370d626b02"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.162"
+version = "1.0.195"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a2a0814352fd64b58489904a44ea8d90cb1a91dcb6b4f5ebabc32c8318e93cb6"
+checksum = "46fe8f8603d81ba86327b23a2e9cdf49e1255fb94a4c5f297f6ee0547178ea2c"
 dependencies = [
  "proc-macro2 1.0.75",
  "quote 1.0.35",
@@ -3402,11 +3402,14 @@ dependencies = [
 name = "tvix-glue"
 version = "0.1.0"
 dependencies = [
+ "bstr",
  "bytes",
  "criterion",
  "data-encoding",
  "lazy_static",
  "nix-compat",
+ "serde",
+ "serde_json",
  "sha2",
  "tempfile",
  "test-case",