fix(native): class-level const array element access (T.Arr[I])

A class-level const array (const Days: array[0..6] of string = (...)) read via
an instance, T.Days[I], returned an empty string on native. The semantic pass
folds the subscript into the field-access node — IsConstant=True with
ConstArraySymbol (the global data label), ConstArrayType (the static-array type)
and PropIndexExpr (the index) — but native's EmitExprToEax IsConstant branch only
handled scalar string/int consts and fell through to an empty string literal.

Added the class-const-array element path: compute
base + (idx - LowBound) * ElemSize and load the element by type (float / string
pointer / narrowed integer), plus a bare-reference case returning the label
address. Mirrors the QBE EmitExpr ConstArraySymbol path. The range- and
enum-indexed class-const-array e2e tests are converted to AssertRunsOnAll.

(Static-array-of-interface element store/read/dispatch remains a separate, larger
follow-up — tracked in bugs.txt; that test stays QBE-only meanwhile.)

All three fixpoints green; 3481 tests pass.

compiler/src/main/pascal/blaise.codegen.native.x86_64.pas

@@ -4830,6 +4830,7 @@ var
   SuppOut: string;
   LSuppNo: string;
   LSuppEnd: string;
+  SCAT: TStaticArrayTypeDesc;
 begin
   if AExpr is TNilLiteral then
   begin
@@ -6477,6 +6478,41 @@ begin
   if (AExpr is TFieldAccessExpr) and TFieldAccessExpr(AExpr).IsConstant then
   begin
     FAE := TFieldAccessExpr(AExpr);
+    { Class-level const ARRAY element access (T.Days[I]): semantic folds the
+      subscript into the field-access node, setting ConstArraySymbol (the global
+      data label), ConstArrayType (the static-array type) and PropIndexExpr (the
+      index).  Compute base + (idx - LowBound)*ElemSize and load — mirrors the
+      QBE EmitSupportsExpr/IsConstant ConstArraySymbol path.  Without this the
+      access fell through to the scalar-string branch and read an empty literal. }
+    if (FAE.ConstArraySymbol <> '') and (FAE.PropIndexExpr <> nil) and
+       (FAE.ConstArrayType <> nil) then
+    begin
+      SCAT := TStaticArrayTypeDesc(FAE.ConstArrayType);
+      Self.EmitExprToEax(FAE.PropIndexExpr);          { index -> %rax }
+      if SCAT.LowBound <> 0 then
+        Self.Emit(Format(#9'subq $%d, %%rax', [SCAT.LowBound]));
+      Self.Emit(Format(#9'imulq $%d, %%rax', [SCAT.ElementType.RawSize()]));
+      Self.Emit(Format(#9'leaq %s(%%rip), %%rcx',
+        [NativeMangle(FAE.ConstArraySymbol)]));
+      Self.Emit(#9'addq %rcx, %rax');
+      if (SCAT.ElementType <> nil) and IsFloatFamily(SCAT.ElementType) then
+        Self.EmitLoadFloat('(%rax)', SCAT.ElementType)
+      else if (SCAT.ElementType <> nil) and SCAT.ElementType.IsString() then
+        Self.Emit(#9'movq (%rax), %rax')
+      else
+      begin
+        Self.Emit(#9'movq (%rax), %rax');
+        Self.EmitNarrowToType(SCAT.ElementType);
+      end;
+      Exit;
+    end;
+    { Bare class-const array reference (no subscript): the data label address. }
+    if FAE.ConstArraySymbol <> '' then
+    begin
+      Self.Emit(Format(#9'leaq %s(%%rip), %%rax',
+        [NativeMangle(FAE.ConstArraySymbol)]));
+      Exit;
+    end;
     if (FAE.ResolvedType <> nil) and FAE.ResolvedType.IsString() then
       Self.EmitStrLitAddr(FAE.ConstString)
     else

compiler/src/test/pascal/cp.test.e2e.staticarray.pas

@@ -418,19 +418,10 @@ const
       T.Free()
     end.
     ''';
-var Output: string; RCode: Integer;
-  Lines: TStringList;
 begin
   if not ToolchainAvailable() then begin Fail('<toolchain-missing>'); Exit end;
-  AssertTrue('compile+run', CompileAndRun(Src, Output, RCode));
-  AssertEquals('exit 0', 0, RCode);
-  Lines := TStringList.Create();
-  try
-    Lines.Text := Trim(Output);
-    AssertEquals('Days[0]', 'Sun', Lines.Strings[0]);
-    AssertEquals('Days[1]', 'Mon', Lines.Strings[1]);
-    AssertEquals('Days[5]', 'Fri', Lines.Strings[2]);
-  finally Lines.Free() end
+  AssertRunsOnAll(Src,
+    'Sun' + Chr(10) + 'Mon' + Chr(10) + 'Fri' + Chr(10), 0);
 end;
 
 procedure TE2EStaticArrayTests.TestRun_ClassConstArray_EnumIndexed;
@@ -452,18 +443,9 @@ const
       P2.Free()
     end.
     ''';
-var Output: string; RCode: Integer;
-  Lines: TStringList;
 begin
   if not ToolchainAvailable() then begin Fail('<toolchain-missing>'); Exit end;
-  AssertTrue('compile+run', CompileAndRun(Src, Output, RCode));
-  AssertEquals('exit 0', 0, RCode);
-  Lines := TStringList.Create();
-  try
-    Lines.Text := Trim(Output);
-    AssertEquals('Names[0]', 'Red', Lines.Strings[0]);
-    AssertEquals('Names[2]', 'Blue', Lines.Strings[1]);
-  finally Lines.Free() end
+  AssertRunsOnAll(Src, 'Red' + Chr(10) + 'Blue' + Chr(10), 0);
 end;
 
 procedure TE2EStaticArrayTests.TestRun_DynArray_High_ReturnsLengthMinusOne;