Rename Collections.pas to Generics.Collections.pas; support dotted uses names

Parser: extend UsesClause to accept dotted unit names (IDENT { DOT IDENT }),
so 'uses Generics.Collections;' parses correctly. The dot-separated
segments are joined into a single string in UsedUnits (e.g. 'Generics.Collections').

RTL: rename Collections.pas → Generics.Collections.pas and update the
unit header to 'unit Generics.Collections' to match FPC's naming and
mirror Delphi's System.Generics.Collections for source-level compatibility.

Grammar: add UnitName rule documenting the dotted-name syntax and its
path-separator semantics.

Tests: 1 new parser test (TestProgramWithDottedUnitName); 569 total, 0 failures.

compiler/src/main/pascal/uParser.pas

@@ -206,21 +206,43 @@ begin
 end;
 
 procedure TParser.ParseUses(AProg: TProgram);
+var
+  UName: string;
 begin
   Expect(tkUses);
   if not Check(tkIdent) then
     raise EParseError.CreateFmt('Expected unit name after ''uses'' at line %d col %d',
       [FCurrent.Line, FCurrent.Col]);
-  AProg.UsedUnits.Add(FCurrent.Value);
+  UName := FCurrent.Value;
   Advance;
+  while Check(tkDot) do
+  begin
+    Advance;
+    if not Check(tkIdent) then
+      raise EParseError.CreateFmt('Expected identifier after ''.'' in unit name at line %d col %d',
+        [FCurrent.Line, FCurrent.Col]);
+    UName := UName + '.' + FCurrent.Value;
+    Advance;
+  end;
+  AProg.UsedUnits.Add(UName);
   while Check(tkComma) do
   begin
     Advance;
     if not Check(tkIdent) then
       raise EParseError.CreateFmt('Expected unit name after '','' at line %d col %d',
         [FCurrent.Line, FCurrent.Col]);
-    AProg.UsedUnits.Add(FCurrent.Value);
+    UName := FCurrent.Value;
     Advance;
+    while Check(tkDot) do
+    begin
+      Advance;
+      if not Check(tkIdent) then
+        raise EParseError.CreateFmt('Expected identifier after ''.'' in unit name at line %d col %d',
+          [FCurrent.Line, FCurrent.Col]);
+      UName := UName + '.' + FCurrent.Value;
+      Advance;
+    end;
+    AProg.UsedUnits.Add(UName);
   end;
   Expect(tkSemicolon);
 end;

compiler/src/test/pascal/cp.test.parser.pas

@@ -18,6 +18,7 @@ type
     procedure TestProgramName;
     procedure TestProgramWithUses;
     procedure TestProgramWithMultipleUses;
+    procedure TestProgramWithDottedUnitName;
 
     { Var block }
     procedure TestSingleVarDecl;
@@ -119,6 +120,20 @@ begin
   end;
 end;
 
+procedure TParserTests.TestProgramWithDottedUnitName;
+var
+  Prog: TProgram;
+begin
+  Prog := ParseSource('program P; uses Generics.Collections, SysUtils; begin end.');
+  try
+    AssertEquals('Uses count', 2, Prog.UsedUnits.Count);
+    AssertEquals('Dotted unit name', 'Generics.Collections', Prog.UsedUnits[0]);
+    AssertEquals('Plain unit name', 'SysUtils', Prog.UsedUnits[1]);
+  finally
+    Prog.Free;
+  end;
+end;
+
 { Var block }
 
 procedure TParserTests.TestSingleVarDecl;

docs/grammar.ebnf

@@ -128,9 +128,17 @@ ImplementationSection
     ;
 
 UsesClause
-    = USES IDENT { COMMA IDENT } SEMICOLON
+    = USES UnitName { COMMA UnitName } SEMICOLON
     ;
 
+UnitName
+    = IDENT { DOT IDENT }
+    ;
+
+(* Dotted unit names map to path-separated files: Generics.Collections →
+ * Generics/Collections.pas.  The dot is part of the name, not a field
+ * access operator; it is only valid in the UsesClause position. *)
+
 
 (* ═══════════════════════════════════════════════════════════════════════════
  * BLOCK

rtl/src/main/pascal/Generics.Collections.pas

@@ -1,6 +1,7 @@
-unit Collections;
+unit Generics.Collections;
 
-// Blaise RTL — generic collections.
+// Blaise RTL — generic collections (mirrors Delphi's System.Generics.Collections
+// and FPC's Generics.Collections for source-level compatibility).
 //
 // NOTE: This file is compiled by the Blaise compiler, not FPC.
 // It uses Blaise syntax and semantics.