Remove #assert token and syntax node

Author: DougGregor

Sources/SwiftParser/TokenPrecedence.swift

@@ -144,8 +144,8 @@ public enum TokenPrecedence: Comparable {
       self = .weakBracketClose
 
     // MARK: Statement keyword punctuator
-    case  // #error, #warning and #assert are statement-like
-    .poundErrorKeyword, .poundWarningKeyword, .poundAssertKeyword:
+    case  // #error, #warning is statement-like
+    .poundErrorKeyword, .poundWarningKeyword:
       self = .stmtKeyword
 
     // MARK: Strong bracketet

gyb_syntax_support/StmtNodes.py

@@ -328,18 +328,4 @@
                    collection_element_name='CatchItem', is_optional=True),
              Child('Body', kind='CodeBlock'),
          ]),
-
-    # e.g. #assert(1 == 2)
-    Node('PoundAssertStmt', name_for_diagnostics="'#assert' directive", kind='Stmt',
-         children=[
-             Child('PoundAssert', kind='PoundAssertToken'),
-             Child('LeftParen', kind='LeftParenToken'),
-             Child('Condition', kind='Expr', name_for_diagnostics='condition',
-                   description='The assertion condition.'),
-             Child('Comma', kind='CommaToken', is_optional=True,
-                   description='The comma after the assertion condition.'),
-             Child('Message', kind='StringLiteralExpr', name_for_diagnostics='message', is_optional=True,
-                   description='The assertion message.'),
-             Child('RightParen', kind='RightParenToken'),
-         ]),
 ]

gyb_syntax_support/Token.py

@@ -227,8 +227,7 @@ def macro_name(self):
     Punctuator('MultilineStringQuote', 'multiline_string_quote',
                text='\\\"\\\"\\\"', classification='StringLiteral'),
 
-    PoundKeyword('PoundAssert', 'assert', text='#assert'),
-
+    # Keywords prefixed with a '#'.
     PoundDirectiveKeyword('PoundSourceLocation', 'sourceLocation',
                           text='#sourceLocation'),
     PoundDirectiveKeyword('PoundWarning', 'warning', text='#warning'),