mutable decl syntax change

compiler/checker/checker.odin

@@ -5952,7 +5952,7 @@ infer_statements :: proc(
 		#partial switch statement.kind {
 		case .Declaration:
 			if statement.expr == ast.INVALID_EXPR {
-				// Value block (`x :: { ... yield v }` / `x T = { ... }`): register the
+				// Value block (`x :: { ... yield v }` / `x T := { ... }`): register the
 				// binding (its declared type when annotated, else left open) and walk
 				// the block body. The build pass resolves the yielded value's type
 				// independently — value blocks don't join the demand fixpoint.
@@ -6026,7 +6026,7 @@ infer_statements :: proc(
 				continue
 			}
 			expected_assignment := types.INVALID
-			if statement.target != ast.INVALID_EXPR {
+			if statement.target != ast.INVALID_EXPR && !symbol.is_valid(statement.name) {
 				expected_assignment = infer_expr(checker, statement.target, locals^[:], pkg, file, demanded, local_types)
 				target_expr := checker.ast_module.exprs[statement.target]
 				if target_expr.kind == .Name && !symbol.is_valid(target_expr.qualifier) {
@@ -6055,7 +6055,7 @@ infer_statements :: proc(
 			// type onto open-constant operands and poison their family. Operands of an
 			// arithmetic RHS resolve from their own authoritative uses.
 			rhs_is_arith := is_arith_kind(checker.ast_module.exprs[statement.expr].kind)
-			if statement.target != ast.INVALID_EXPR {
+			if statement.target != ast.INVALID_EXPR && !symbol.is_valid(statement.name) {
 				target_type := expected_assignment
 				target_expr := checker.ast_module.exprs[statement.target]
 				if target_expr.kind == .Name && !symbol.is_valid(target_expr.qualifier) {
@@ -10922,7 +10922,7 @@ build_block :: proc(
 		}
 		switch statement.kind {
 		case .Declaration:
-			// A value block (`x :: { ... yield v }` / `x T = { ... }`): the parser
+			// A value block (`x :: { ... yield v }` / `x T := { ... }`): the parser
 			// leaves `expr` invalid and stashes the block in `body`. Build it, then
 			// declare the local from the yielded value (its type for an untyped `::`).
 			if statement.expr == ast.INVALID_EXPR {
@@ -11123,7 +11123,7 @@ build_block :: proc(
 				ctx.problematic^ = ctx.problematic^ || checker.module.exprs[value].kind == .Invalid
 			}
 		case .Assignment:
-			if statement.target != ast.INVALID_EXPR {
+			if statement.target != ast.INVALID_EXPR && !symbol.is_valid(statement.name) {
 				target_expr := build_expr(
 					checker, statement.target, ctx.locals^[:], ctx.global_reads, ctx.calls,
 					types.INVALID, ctx.pkg, ctx.file,
@@ -14349,18 +14349,6 @@ build_globals :: proc(checker: ^Checker) {
 			)
 			expr = invalid_hir_expr(checker, global.span, diagnostic)
 		}
-		if !global.immutable {
-			if !types.is_valid(global.type) {
-				diagnostic = source.addf(
-					checker.diagnostics,
-					global.span,
-					"mutable global '%s' requires a type annotation",
-					symbol_text(checker, global.name),
-				)
-				global_type = types.I64
-				expr = invalid_hir_expr(checker, global.span, diagnostic, global_type)
-			}
-		}
 		static_value, is_static := static_integer_value(&checker.module, expr)
 		is_static = is_static && diagnostic == source.INVALID_DIAGNOSTIC && global.immutable
 		_ = hir.global_id(len(checker.module.globals))