[beta] Bump bootstrap compiler to 1.27.2

[pietroalbini]

This PR bumps the beta bootstrap compiler to 1.27.2.

• The original cargo version was wrong: the current one is not 0.28.0, but 1.27.0 (since Make cargo-the-binary version the same as the Rust version cargo#5083). Should the forge be updated?
• The updated date is the correct one for rustc, but the wrong one for cargo. I think that shouldn't cause any problem, but it's better to ask.

r? @Mark-Simulacrum

[rust-highfive]

⚠️ Warning ⚠️

• Pull requests are usually filed against the master branch for this repo, but this one is against beta. Please double check that you specified the right target!

[Mark-Simulacrum]

You'll need to revert the cargo version change; we distribute cargo under the old versioning scheme. The date is correct I think, not certain though. r=me once Travis passes though.

[alexcrichton]

@bors: r=Mark-Simulacrum

[bors]

📌 Commit 1c5f883 has been approved by Mark-Simulacrum

[pietroalbini]

@bors p=1

[pietroalbini]

@bors p=2

[bors]

⌛ Testing commit 1c5f883 with merge 90586ed436cf2a4ae145559ece4daa2ad4ca5943...

[bors]

💔 Test failed - status-travis

[rust-highfive]

The job dist-powerpc64le-linux of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[02:57:23] [RUSTC-TIMING] rustc_errors test:false 23.852
[02:57:27]    Compiling rustc-ap-syntax v156.0.0
[02:58:13] [RUSTC-TIMING] syntex_syntax test:false 94.720
[02:58:29]    Compiling racer v2.0.14
The job exceeded the maximum time limit for jobs, and has been terminated.

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[Mark-Simulacrum]

@bors retry

[bors]

⌛ Testing commit 1c5f883 with merge 7293eab...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: Mark-Simulacrum
Pushing 7293eab to beta...