update error messages in ui tests

Author: tspiteri

tests/ui/resolve/issue-50599.stderr

@@ -6,6 +6,10 @@ LL |     const M: usize = (f64::from(N) * std::f64::LOG10_2) as usize;
    |
 help: consider importing one of these items
    |
+LL + use std::f128::consts::LOG10_2;
+   |
+LL + use std::f16::consts::LOG10_2;
+   |
 LL + use std::f32::consts::LOG10_2;
    |
 LL + use std::f64::consts::LOG10_2;

tests/ui/resolve/issue-73427.stderr

@@ -107,6 +107,10 @@ LL |     (E::TupleWithFields(/* fields */)).foo();
    |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 help: consider importing one of these items instead
    |
+LL + use std::f128::consts::E;
+   |
+LL + use std::f16::consts::E;
+   |
 LL + use std::f32::consts::E;
    |
 LL + use std::f64::consts::E;

tests/ui/resolve/privacy-enum-ctor.stderr

@@ -84,6 +84,10 @@ LL |     let _: E = m::f;
    |                   ~
 help: consider importing one of these items instead
    |
+LL + use std::f128::consts::E;
+   |
+LL + use std::f16::consts::E;
+   |
 LL + use std::f32::consts::E;
    |
 LL + use std::f64::consts::E;
@@ -121,6 +125,10 @@ LL |     let _: E = (E::Fn(/* fields */));
    |                ~~~~~~~~~~~~~~~~~~~~~
 help: consider importing one of these items instead
    |
+LL + use std::f128::consts::E;
+   |
+LL + use std::f16::consts::E;
+   |
 LL + use std::f32::consts::E;
    |
 LL + use std::f64::consts::E;