Rollup merge of #79193 - tmiasko:revert-78969-normalize, r=davidtwco

Revert #78969 "Normalize function type during validation"

Closes #79066.
Reopens #78442.

src/test/ui/issues/issue-50865-private-impl-trait/auxiliary/lib.rs

@@ -1,3 +1,7 @@
+// revisions: default miropt
+//[miropt]compile-flags: -Z mir-opt-level=2
+// ~^ This flag is for #77668, it used to be ICE.
+
 #![crate_type = "lib"]
 
 pub fn bar<P>( // Error won't happen if "bar" is not generic

src/test/ui/mir/mir-inlining/ice-issue-77306-1.rs

@@ -1,27 +1,17 @@
-// Regression test for various issues related to normalization & inlining.
-// * #68347, #77306, #77668 - missed normalization during inlining.
-// * #78442 - missed normalization in validator after inlining.
-//
-// build-pass
+// run-pass
 // compile-flags:-Zmir-opt-level=2
 
+// Previously ICEd because we did not normalize during inlining,
+// see https://github.com/rust-lang/rust/pull/77306 for more discussion.
+
 pub fn write() {
     create()()
 }
 
-pub fn write_generic<T>(_t: T) {
-    hide()();
-}
-
 pub fn create() -> impl FnOnce() {
    || ()
 }
 
-pub fn hide() -> impl Fn() {
-    write
-}
-
 fn main() {
     write();
-    write_generic(());
 }