[EXPERIMENT 2] Pin compiler cc @ 1.2.20

Author: jieyouxu

Cargo.lock

@@ -462,9 +462,9 @@ version = "0.1.0"
 
 [[package]]
 name = "cc"
-version = "1.2.28"
+version = "1.2.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4ad45f4f74e4e20eaa392913b7b33a7091c87e59628f4dd27888205ad888843c"
+checksum = "04da6a0d40b948dfc4fa8f5bbf402b0fc1a64a28dbf7d12ffd683550f2c1b63a"
 dependencies = [
  "jobserver",
  "libc",

compiler/rustc_llvm/Cargo.toml

@@ -11,7 +11,7 @@ libc = "0.2.73"
 [build-dependencies]
 # tidy-alphabetical-start
 # `cc` updates often break things, so we pin it here.
-cc = "=1.2.28"
+cc = "=1.2.20"
 # tidy-alphabetical-end
 
 [features]