Don't bother with `stamp` utility

That was just used because Travis doesn't have time stamps on all log
lines, but Azure does, so no need to add our own.

.azure-pipelines/steps/linux.yml

@@ -8,9 +8,6 @@ steps:
 - bash: |
     sudo apt install gdb
 
-    curl -fo $HOME/stamp https://s3-us-west-1.amazonaws.com/rust-lang-ci2/rust-ci-mirror/2017-03-17-stamp-x86_64-unknown-linux-musl
-    chmod +x $HOME/stamp
-
     export PATH=$PATH:$HOME/.local/bin:$HOME/Library/Python/2.7/bin/:$HOME
     echo "##vso[task.prependpath]$HOME/.local/bin"
     echo "##vso[task.prependpath]$HOME/Library/Python/2.7/bin"

.azure-pipelines/steps/macos.yml

@@ -9,9 +9,6 @@ steps:
     curl -fo /usr/local/bin/sccache https://s3-us-west-1.amazonaws.com/rust-lang-ci2/rust-ci-mirror/2018-04-02-sccache-x86_64-apple-darwin
     chmod +x /usr/local/bin/sccache
 
-    curl -fo /usr/local/bin/stamp https://s3-us-west-1.amazonaws.com/rust-lang-ci2/rust-ci-mirror/2017-03-17-stamp-x86_64-apple-darwin
-    chmod +x /usr/local/bin/stamp
-
     export CC=`pwd`/clang+llvm-7.0.0-x86_64-apple-darwin/bin/clang
     echo "##vso[task.setvariable variable=CC]$CC"
 

.azure-pipelines/steps/run-script.yml

@@ -6,7 +6,7 @@ steps:
     date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
 
     which sccache
-    stamp sh -x -c "$RUN_SCRIPT"
+    "$RUN_SCRIPT"
 
     date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
   env: