Fix bad suggestions when initializing enum as struct

compiler/rustc_resolve/src/diagnostics.rs

@@ -1271,6 +1271,7 @@ impl<'a> Resolver<'a> {
         let mut seen_modules = FxHashSet::default();
         let mut worklist = vec![(start_module, Vec::<ast::PathSegment>::new(), true)];
         let mut worklist_via_import = vec![];
+        let mut seen_exact_match = false;
 
         while let Some((in_module, path_segments, accessible)) = match worklist.pop() {
             None => worklist_via_import.pop(),
@@ -1313,6 +1314,15 @@ impl<'a> Resolver<'a> {
                     }
                 }
 
+                // Note if we find an in-scope exact match on the identifier we are looking for
+                if ident.name == lookup_ident.name
+                    && ns == namespace
+                    && ptr::eq(in_module, parent_scope.module)
+                {
+                    seen_exact_match = true;
+                    return;
+                }
+
                 // collect results based on the filter function
                 // avoid suggesting anything from the same module in which we are resolving
                 // avoid suggesting anything with a hygienic name
@@ -1406,6 +1416,12 @@ impl<'a> Resolver<'a> {
             })
         }
 
+        // If we've seen an exact match on the ident, assume correct intent from the user
+        // (ie. the user meant to use the ident like this) and clear any import candidates
+        if seen_exact_match {
+            candidates.clear();
+        }
+
         // If only some candidates are accessible, take just them
         if !candidates.iter().all(|v: &ImportSuggestion| !v.accessible) {
             candidates = candidates.into_iter().filter(|x| x.accessible).collect();

src/test/ui/hygiene/globs.stderr

@@ -37,8 +37,6 @@ LL | n!(f);
 LL |         n!(f);
    |            ^ not found in this scope
    |
-   = note: consider importing this function:
-           foo::f
    = note: this error originates in the macro `n` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0425]: cannot find function `f` in this scope
@@ -50,8 +48,6 @@ LL | n!(f);
 LL |                 f
    |                 ^ not found in this scope
    |
-   = note: consider importing this function:
-           foo::f
    = note: this error originates in the macro `n` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 4 previous errors

src/test/ui/resolve/issue-3907.stderr

@@ -8,10 +8,6 @@ help: you might have meant to use `#![feature(trait_alias)]` instead of a `type`
    |
 LL | trait Foo = dyn issue_3907::Foo;
    |
-help: consider importing this trait instead
-   |
-LL | use issue_3907::Foo;
-   |
 
 error: aborting due to previous error
 

src/test/ui/span/issue-35987.stderr

@@ -3,11 +3,6 @@ error[E0404]: expected trait, found type parameter `Add`
    |
 LL | impl<T: Clone, Add> Add for Foo<T> {
    |                     ^^^ not a trait
-   |
-help: consider importing this trait instead
-   |
-LL | use std::ops::Add;
-   |
 
 error: aborting due to previous error
 

src/test/ui/suggestions/init-enum-as-struct.rs

@@ -0,0 +1,23 @@
+pub type Foos = i32;
+
+pub enum Foo {
+    A,
+    B,
+    C,
+}
+
+mod module0 {
+    pub struct Foo {
+        a: i32,
+    }
+}
+mod module1 {
+    pub struct Foo {}
+}
+mod module2 {
+    pub enum Foo {}
+}
+
+fn main() {
+    let foo = Foo { b: 0 }; //~ expected struct, variant or union type, found enum `Foo`
+}

src/test/ui/suggestions/init-enum-as-struct.stderr

@@ -0,0 +1,12 @@
+error[E0574]: expected struct, variant or union type, found enum `Foo`
+  --> $DIR/init-enum-as-struct.rs:22:15
+   |
+LL | pub type Foos = i32;
+   | -------------------- similarly named type alias `Foos` defined here
+...
+LL |     let foo = Foo { b: 0 };
+   |               ^^^ help: a type alias with a similar name exists: `Foos`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0574`.