Start work on compressing RPC messages

Co-Authored-By: Antonio Scandurra <me@as-cii.com>

Cargo.lock

@@ -867,6 +867,9 @@ name = "cc"
 version = "1.0.67"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3c69b077ad434294d3ce9f1f6143a2a4b89a8a2d54ef813d85003a4fd1137fd"
+dependencies = [
+ "jobserver",
+]
 
 [[package]]
 name = "cexpr"
@@ -2614,6 +2617,15 @@ version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dd25036021b0de88a0aff6b850051563c6516d0bf53f8638938edbb9de732736"
 
+[[package]]
+name = "jobserver"
+version = "0.1.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af25a77299a7f711a01975c35a6a424eb6862092cc2d6c72c4ed6cbc56dfc1fa"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "jpeg-decoder"
 version = "0.1.22"
@@ -6037,4 +6049,34 @@ dependencies = [
  "serde 1.0.125",
  "smol",
  "tempdir",
+ "zstd",
+]
+
+[[package]]
+name = "zstd"
+version = "0.9.0+zstd.1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "07749a5dc2cb6b36661290245e350f15ec3bbb304e493db54a1d354480522ccd"
+dependencies = [
+ "zstd-safe",
+]
+
+[[package]]
+name = "zstd-safe"
+version = "4.1.1+zstd.1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c91c90f2c593b003603e5e0493c837088df4469da25aafff8bce42ba48caf079"
+dependencies = [
+ "libc",
+ "zstd-sys",
+]
+
+[[package]]
+name = "zstd-sys"
+version = "1.6.1+zstd.1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "615120c7a2431d16cf1cf979e7fc31ba7a5b5e5707b29c8a99e5dbf8a8392a33"
+dependencies = [
+ "cc",
+ "libc",
 ]