hir: Remove EnumItemDiscriminant from HIR

[varun-r-mallya]

gcc/rust/ChangeLog:

	* ast/rust-ast-collector.cc (TokenCollector::visit): Removed.
	* backend/rust-compile-item.h (CompileItem::visit): Remove EnumItemDiscriminant case.
	* backend/rust-compile-stmt.h (CompileStmt::visit): Remove EnumItemDiscriminant case.
	* checks/errors/borrowck/rust-bir-builder-expr-stmt.h (BIRBuilderExprStmt::visit):
	Remove EnumItemDiscriminant case.
	* checks/errors/borrowck/rust-bir-builder-struct.h (BIRBuilderStruct::visit): Remove
	EnumItemDiscriminant case.
	* checks/errors/borrowck/rust-function-collector.h (FunctionCollector::visit): Remove
	EnumItemDiscriminant case.
	* checks/errors/privacy/rust-privacy-reporter.cc (PrivacyReporter::visit): Remove
	EnumItemDiscriminant implementation.
	* checks/errors/privacy/rust-privacy-reporter.h (PrivacyReporter::visit): Remove
	EnumItemDiscriminant declaration.
	* checks/errors/rust-const-checker.cc (ConstChecker::visit): Remove EnumItemDiscriminant
	implementation.
	* checks/errors/rust-const-checker.h (ConstChecker::visit): Remove EnumItemDiscriminant
	declaration.
	* checks/errors/rust-hir-pattern-analysis.cc (PatternChecker::visit): Remove
	EnumItemDiscriminant implementation.
	* checks/errors/rust-hir-pattern-analysis.h (PatternChecker::visit): Remove
	EnumItemDiscriminant declaration.
	* checks/errors/rust-unsafe-checker.cc (UnsafeChecker::visit): Remove
	EnumItemDiscriminant implementation.
	* checks/errors/rust-unsafe-checker.h (UnsafeChecker::visit): Remove
	EnumItemDiscriminant declaration.
	* hir/rust-hir-dump.cc (Dump::visit): Remove EnumItemDiscriminant implementation.
	* hir/rust-hir-dump.h (Dump::visit): Remove EnumItemDiscriminant declaration.
	* hir/tree/rust-hir-full-decls.h: Remove EnumItemDiscriminant forward declaration.
	* hir/tree/rust-hir-item.cc (EnumItemDiscriminant::as_string): Remove implementation.
	(EnumItemDiscriminant::accept_vis): Remove implementation.
	* hir/tree/rust-hir-item.h: Remove EnumItemDiscriminant class definition.
	* hir/tree/rust-hir-visitor.h (HIRFullVisitor::visit): Remove EnumItemDiscriminant
	declaration.
	(HIRStmtVisitor::visit): Remove EnumItemDiscriminant declaration.
	* hir/tree/rust-hir.cc (EnumItemDiscriminant::as_string): Remove implementation.
	(EnumItemDiscriminant::accept_vis): Remove implementation.
	* typecheck/rust-hir-type-check-enumitem.cc (TypeCheckEnumItem::Resolve): Remove
	EnumItemDiscriminant case.
	(TypeCheckEnumItem::visit): Remove EnumItemDiscriminant implementation.
	* typecheck/rust-hir-type-check-enumitem.h (TypeCheckEnumItem::visit): Remove
	EnumItemDiscriminant declaration.
	* typecheck/rust-hir-type-check-stmt.h (TypeCheckStmt::visit): Remove EnumItemDiscriminant case.

Addresses #3340

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[varun-r-mallya]

make check-rust does not run on my machine and gives an OOM error. I will be developing on my machine and testing here due to this

[powerboat9]

How much ram do you have?

[varun-r-mallya]

How much ram do you have?

I have 32 GBs of RAM currently. I think this is an issue particularly due a memory leak I am making in the code. For my other PR, I ran make check-rust multiple times with no issues.

[powerboat9]

Are you sure this PR is the one you're OOMing on?

Edit: is the code causing the memory leak pushed?

[varun-r-mallya]

https://github.com/Rust-GCC/gccrs/pull/3698#issuecomment-2781092615 Yeah, I just ran the test locally, it did cause an OOM. Fedora shut it down.