change placeholder pattern in deduplicated type errors

src/Type.zig

@@ -4158,8 +4158,8 @@ fn shouldDedupeType(ty: Type, ctx: *Comparison, pt: Zcu.PerThread) error{OutOfMe
 
         const type_len: i32 = @intCast(discarding.count);
 
-        const placeholder_len: i32 = 3;
-        const min_saved_bytes: i32 = 10;
+        const placeholder_len: i32 = 1;
+        const min_saved_bytes: i32 = 20;
 
         const saved_bytes = (type_len - placeholder_len) * (occ - 1);
         const max_placeholders = 7; // T to Z
@@ -4192,7 +4192,7 @@ pub const Comparison = struct {
         index: u8,
 
         pub fn format(p: Placeholder, writer: *std.Io.Writer) error{WriteFailed}!void {
-            return writer.print("<{c}>", .{p.index + 'T'});
+            return writer.print("{c}", .{p.index + 'T'});
         }
     };
 

test/cases/compile_errors/pointer_attributes_checked_when_coercing_pointer_to_anon_literal.zig

@@ -16,8 +16,7 @@ comptime {
 //
 // :2:29: error: expected type '[][]const u8', found '*const [2][]const u8'
 // :2:29: note: cast discards const qualifier
-// :6:31: error: expected type '*<T>', found '*const <T>'
-// :6:31: note: <T> = [2][]const u8
+// :6:31: error: expected type '*[2][]const u8', found '*const [2][]const u8'
 // :6:31: note: cast discards const qualifier
 // :11:19: error: expected type '*tmp.S', found '*const tmp.S'
 // :11:19: note: cast discards const qualifier

test/cases/compile_errors/type_dedupe.zig

@@ -1,18 +1,18 @@
-const SomeVeryLongName = struct {};
+const SomeVeryVeryVeryLongName = struct {};
 
-fn foo(a: *SomeVeryLongName) void {
+fn foo(a: *SomeVeryVeryVeryLongName) void {
     _ = a;
 }
 
 export fn entry() void {
-    const a: SomeVeryLongName = .{};
+    const a: SomeVeryVeryVeryLongName = .{};
 
     foo(a);
 }
 
 // error
 //
-// :10:9: error: expected type '*<T>', found '<T>'
-// :10:9: note: <T> = tmp.SomeVeryLongName
-// :1:26: note: struct declared here
+// :10:9: error: expected type '*T', found 'T'
+// :10:9: note: T = tmp.SomeVeryVeryVeryLongName
+// :1:34: note: struct declared here
 // :3:11: note: parameter type declared here

test/cases/compile_errors/type_mismatch_with_tuple_concatenation.zig

@@ -5,5 +5,5 @@ export fn entry() void {
 
 // error
 //
-// :3:11: error: expected type '@TypeOf(.{})', found 'struct { comptime <T> = 1, comptime <T> = 2, comptime <T> = 3 }'
-// :3:11: note: <T> = comptime_int
+// :3:11: error: expected type '@TypeOf(.{})', found 'struct { comptime T = 1, comptime T = 2, comptime T = 3 }'
+// :3:11: note: T = comptime_int