Auto merge of #28900 - cristicbz:typos, r=alexcrichton

I found these automatically, but fixed them manually to ensure the semantics are correct. I know things like these are hardly important, since they only marginally improve clarity. But at least for me typos and simple grammatical errors trigger an---unjustified---sense of unprofessionalism, despite the fact that I make them all the time and I understand that they're the sort of thing that is bound to slip through review.  

Anyway, to find most of these I used:

  * `ag '.*//.*(\b[A-Za-z]{2,}\b) \1\b'` for repeated words

  * `ag '\b(the|this|those|these|a|it) (a|the|this|those|these|it)\b'` to find constructs like 'the this' etc. many false positives, but not too hard to scroll through them to actually find the mistakes.

  * `cat ../../typos.txt | paste -d'|' - - - - - - - - - - - - - - - - - - - - - - | tr '\n' '\0' | xargs -0 -P4 -n1 ag`. Hacky way to find misspellings, but it works ok. I got `typos.txt` from [Wikipedia](https://en.wikipedia.org/wiki/Wikipedia:Lists_of_common_misspellings/For_machines)

* `ag '.*//.* a ([ae][a-z]|(o[^n])|(i[a-rt-z]))'` to find places where 'a' was followed by a vowel (requiring 'an' instead).

I also used a handful more one off regexes that are too boring to reproduce here.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libcoretest/num/dec2flt/mod.rs b/src/libcoretest/num/dec2flt/mod.rs
index 131cf629575..51fea6e0171 100644
--- a/src/libcoretest/num/dec2flt/mod.rs
+++ b/src/libcoretest/num/dec2flt/mod.rs
@@ -16,7 +16,7 @@ use test;
 mod parse;
 mod rawfp;
 
-// Take an float literal, turn it into a string in various ways (that are all trusted
+// Take a float literal, turn it into a string in various ways (that are all trusted
 // to be correct) and see if those strings are parsed back to the value of the literal.
 // Requires a *polymorphic literal*, i.e. one that can serve as f64 as well as f32.
 macro_rules! test_literal {