Refactor snapshot build (#2825)

Instead of using core/snapshot_creator.rs, instead two crates are
introduced which allow building the snapshot during build.rs.

Rollup is removed and replaced with our own bundler. This removes
the Node build dependency. Modules in //js now use Deno-style imports
with file extensions, rather than Node style extensionless imports.

This improves incremental build time when changes are made to //js files
by about 40 seconds.

1 files changed, 22 insertions, 0 deletions

diff --git a/deno_typescript/BUILD.gn b/deno_typescript/BUILD.gn
new file mode 100644
index 000000000..0b868c7bd
--- /dev/null
+++ b/deno_typescript/BUILD.gn
@@ -0,0 +1,22 @@
+import("//build_extra/rust/rust.gni")
+
+rust_rlib("deno_typescript") {
+  source_root = "lib.rs"
+  generated_source_dir = "."
+  extern = [
+    {
+      label = "../core:deno"
+      crate_name = "deno"
+      crate_type = "rlib"
+    },
+    {
+      label = "$rust_build:serde_derive"
+      crate_name = "serde_derive"
+      crate_type = "proc_macro"
+    },
+  ]
+  extern_rlib = [
+    "serde_json",
+    "serde",
+  ]
+}