ASTScope: Fix SourceFileScope source range

A SourceFile might contain TopLevelCodeDecls with guard statements,
which introduce names until the end of the file, so plumb that
through.

Author: slavapestov

lib/AST/ASTScopeCreation.cpp

@@ -994,10 +994,8 @@ ASTSourceFileScope::expandAScopeThatCreatesANewInsertionPoint(
     ScopeCreator &scopeCreator) {
   ASTScopeAssert(SF, "Must already have a SourceFile.");
   ArrayRef<Decl *> decls = SF->getTopLevelDecls();
-  // Assume that decls are only added at the end, in source order
-  Optional<SourceLoc> endLoc = None;
-  if (!decls.empty())
-    endLoc = decls.back()->getEndLoc();
+
+  SourceLoc endLoc = getSourceRangeOfThisASTNode().End;
 
   std::vector<ASTNode> newNodes(decls.begin(), decls.end());
   insertionPoint =

test/NameLookup/scope_map_top_level.swift

@@ -29,20 +29,20 @@ var i: Int = b.my_identity()
 // CHECK-EXPANDED-NEXT: ASTSourceFileScope {{.*}}, (uncached) [1:1 - 61:1] 'SOURCE_DIR{{[/\\]}}test{{[/\\]}}NameLookup{{[/\\]}}scope_map_top_level.swift'
 // CHECK-EXPANDED-NEXT: |-NominalTypeDeclScope {{.*}}, [4:1 - 4:13]
 // CHECK-EXPANDED-NEXT:   `-NominalTypeBodyScope {{.*}}, [4:11 - 4:13]
-// CHECK-EXPANDED-NEXT: `-TopLevelCodeScope {{.*}}, [6:1 - 21:28]
-// CHECK-EXPANDED-NEXT:   `-BraceStmtScope {{.*}}, [6:1 - 21:28]
+// CHECK-EXPANDED-NEXT: `-TopLevelCodeScope {{.*}}, [6:1 - 61:1]
+// CHECK-EXPANDED-NEXT:   `-BraceStmtScope {{.*}}, [6:1 - 61:1]
 // CHECK-EXPANDED-NEXT:     |-PatternEntryDeclScope {{.*}}, [6:5 - 6:15] entry 0 'a'
 // CHECK-EXPANDED-NEXT:       `-PatternEntryInitializerScope {{.*}}, [6:15 - 6:15] entry 0 'a'
-// CHECK-EXPANDED-NEXT:     `-TopLevelCodeScope {{.*}}, [8:1 - 21:28]
-// CHECK-EXPANDED-NEXT:       `-BraceStmtScope {{.*}}, [8:1 - 21:28]
-// CHECK-EXPANDED-NEXT:         `-GuardStmtScope {{.*}}, [8:1 - 21:28]
-// CHECK-EXPANDED-NEXT:           `-ConditionalClausePatternUseScope, [8:15 - 21:28] let b{{\??}}
+// CHECK-EXPANDED-NEXT:     `-TopLevelCodeScope {{.*}}, [8:1 - 61:1]
+// CHECK-EXPANDED-NEXT:       `-BraceStmtScope {{.*}}, [8:1 - 61:1]
+// CHECK-EXPANDED-NEXT:         `-GuardStmtScope {{.*}}, [8:1 - 61:1]
+// CHECK-EXPANDED-NEXT:           `-ConditionalClausePatternUseScope, [8:15 - 61:1] let b{{\??}}
 // CHECK-EXPANDED-NEXT:             |-ConditionalClauseInitializerScope, [8:15 - 8:15]
 // CHECK-EXPANDED-NEXT:             |-AbstractFunctionDeclScope {{.*}}, [11:1 - 11:19] 'foo(x:)'
 // CHECK-EXPANDED-NEXT:               |-ParameterListScope {{.*}}, [11:9 - 11:16]
 // CHECK-EXPANDED-NEXT:               `-FunctionBodyScope {{.*}}, [11:18 - 11:19]
-// CHECK-EXPANDED-NEXT:             `-TopLevelCodeScope {{.*}}, [13:1 - 21:28]
-// CHECK-EXPANDED-NEXT:               `-BraceStmtScope {{.*}}, [13:1 - 21:28]
+// CHECK-EXPANDED-NEXT:             `-TopLevelCodeScope {{.*}}, [13:1 - 61:1]
+// CHECK-EXPANDED-NEXT:               `-BraceStmtScope {{.*}}, [13:1 - 61:1]
 // CHECK-EXPANDED-NEXT:                 |-PatternEntryDeclScope {{.*}}, [13:5 - 13:9] entry 0 'c'
 // CHECK-EXPANDED-NEXT:                   `-PatternEntryInitializerScope {{.*}}, [13:9 - 13:9] entry 0 'c'
 // CHECK-EXPANDED-NEXT:                 |-TypeAliasDeclScope {{.*}}, [15:1 - 15:15]
@@ -51,8 +51,8 @@ var i: Int = b.my_identity()
 // CHECK-EXPANDED-NEXT:                     `-AbstractFunctionDeclScope {{.*}}, [18:3 - 18:43] 'my_identity()'
 // CHECK-EXPANDED-NEXT:                       `-FunctionBodyScope {{.*}}, [18:29 - 18:43]
 // CHECK-EXPANDED-NEXT:                         `-BraceStmtScope {{.*}}, [18:29 - 18:43]
-// CHECK-EXPANDED-NEXT:                 `-TopLevelCodeScope {{.*}}, [21:1 - 21:28]
-// CHECK-EXPANDED-NEXT:                   `-BraceStmtScope {{.*}}, [21:1 - 21:28]
+// CHECK-EXPANDED-NEXT:                 `-TopLevelCodeScope {{.*}}, [21:1 - 61:1]
+// CHECK-EXPANDED-NEXT:                   `-BraceStmtScope {{.*}}, [21:1 - 61:1]
 // CHECK-EXPANDED-NEXT:                     `-PatternEntryDeclScope {{.*}}, [21:5 - 21:28] entry 0 'i'
 // CHECK-EXPANDED-NEXT:                       `-PatternEntryInitializerScope {{.*}}, [21:14 - 21:28] entry 0 'i'