upper_case_acronyms: don't warn on public items

Fixes #6803

changelog: upper_case_acronyms: ignore public items

tests/ui-toml/upper_case_acronyms_aggressive/upper_case_acronyms.rs

@@ -19,4 +19,9 @@ enum Flags {
 struct GCCLLVMSomething; // linted with cfg option, beware that lint suggests `GccllvmSomething` instead of
                          // `GccLlvmSomething`
 
+// don't warn on public items
+pub struct MIXEDCapital;
+
+pub struct FULLCAPITAL;
+
 fn main() {}

tests/ui/upper_case_acronyms.rs

@@ -19,4 +19,8 @@ enum Flags {
 struct GCCLLVMSomething; // linted with cfg option, beware that lint suggests `GccllvmSomething` instead of
                          // `GccLlvmSomething`
 
+// public items must not be linted
+pub struct NOWARNINGHERE;
+pub struct ALSONoWarningHERE;
+
 fn main() {}