Rollup merge of #110791 - compiler-errors:negative-bounds, r=oli-obk

Implement negative bounds for internal testing purposes

Implements partial support the `!` negative polarity on trait bounds. This is incomplete, but should allow us to at least be able to play with the feature.

Not even gonna consider them as a public-facing feature, but I'm implementing them because would've been nice to have in UI tests, for example in #110671.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/tools/rustfmt/tests/target/negative-bounds.rs b/src/tools/rustfmt/tests/target/negative-bounds.rs
new file mode 100644
index 00000000000..4fb35cccf66
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/negative-bounds.rs
@@ -0,0 +1,11 @@
+fn negative()
+where
+    i32: !Copy,
+{
+}
+
+fn maybe_const_negative()
+where
+    i32: ~const !Copy,
+{
+}