Remove unnecessary dummy span checks

[estebank]

The emitter already verifies wether a given span note or span label
can be emitted to the output. If it can't, because it is a dummy
span, it will be either elided for labels or emitted as an unspanned
note/help when applicable.

[rust-highfive]

r? @varkor

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[estebank]

CC #55669

[TimNN]

Ping from triage @varkor: This PR requires your review.

Ping form triage @estebank: It looks like your PR failed on travis and needs a rebase.

[varkor]

Sorry, I was putting off looking at this because I saw it was marked as "WIP". Is this ready to review now?

[estebank]

I'll come back to this soon. I need to add some code to special case the emitter so the notes appear indented instead as left aligned when span == DUMMY_SP.

[stokhos]

Ping from triage @estebank Have you been able to make any progress on this

[estebank]

@stokhos completed

@varkor ready for review

[varkor]

Looks good to me!

[estebank]

@bors r=varkor

[bors]

📌 Commit f077990 has been approved by varkor

[bors]

⌛ Testing commit f077990 with merge 72754e875b5e5ce1b16709e3621b5547432dc5ab...

[bors]

💔 Test failed - checks-travis

[rust-highfive]

The job x86_64-apple 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.

travis_fold:start:before_install.1
travis_time:start:267d892f
$ pip install --user awscli; export PATH=$PATH:$HOME/.local/bin:$HOME/Library/Python/2.7/bin/
Collecting awscli
  Downloading https://files.pythonhosted.org/packages/04/be/6529423f80959e3c9ce05d1425e4237e3c3a01bb4b8a83061ae57ddfa5ab/awscli-1.16.93-py2.py3-none-any.whl (1.4MB)
  Downloading https://files.pythonhosted.org/packages/50/09/c53398e0005b11f7ffb27b7aa720c617aba53be4fb4f4f3f06b9b5c60f28/docutils-0.14-py2-none-any.whl (543kB)
Collecting rsa<=3.5.0,>=3.1.2 (from awscli)
  Downloading https://files.pythonhosted.org/packages/e1/ae/baedc9cb175552e95f3395c43055a6a5e125ae4d48a1d7a924baca83e92e/rsa-3.4.2-py2.py3-none-any.whl (46kB)
Collecting colorama<=0.3.9,>=0.2.5 (from awscli)
---
[00:03:22]    Compiling serde_derive v1.0.81
[00:03:24]    Compiling toml v0.4.10
[00:03:24]    Compiling serde_json v1.0.33
[00:03:35]    Compiling bootstrap v0.0.0 (/Users/travis/build/rust-lang/rust/src/bootstrap)
No output has been received in the last 30m0s, this potentially indicates a stalled build or something wrong with the build itself.
Check the details on how to adjust your build configuration on: https://docs.travis-ci.com/user/common-build-problems/#Build-times-out-because-no-output-was-received
The build 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)

[varkor]

@bors retry

[bors]

⌛ Testing commit f077990 with merge 76c87a1...

[bors]

☀️ Test successful - checks-travis, status-appveyor
Approved by: varkor
Pushing 76c87a1 to master...