don't uppercase error messages

a more general version of https://github.com/rust-lang/rust/pull/146080.

after a bit of hacking in [`fluent.rs`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_fluent_macro/src/fluent.rs), i discovered that i'm not the only one that is bad at following guidelines :sweat_smile:. this pr lowercases the first letter of all the error messages in the codebase.

(i did not change things that are traditionally uppercased such as _MIR_, _ABI_ or _C_)

i think it's reasonable to run a `@bors try` so all the test suite is checked, as i cannot run some of the tests on my machine. i double checked (and replaced manually) all the old error messages, but better be safe than sorry.

in the future i will try to add a check in `x test tidy` that errors if an error message starts with an uppercase letter.

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/rustc_const_eval/messages.ftl b/compiler/rustc_const_eval/messages.ftl
index 60518dafbf2..700d7c26752 100644
--- a/compiler/rustc_const_eval/messages.ftl
+++ b/compiler/rustc_const_eval/messages.ftl
@@ -457,7 +457,7 @@ const_eval_validation_failure =
     it is undefined behavior to use this value
 
 const_eval_validation_failure_note =
-    The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
+    the rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
 
 const_eval_validation_front_matter_invalid_value = constructing invalid value
 const_eval_validation_front_matter_invalid_value_with_path = constructing invalid value at {$path}