Lock in behaviour for previously reported parse bugs

test/corpus/declarations.txt

@@ -1123,6 +1123,50 @@ lambda parameters with block-locals
       locals: (identifier))
     body: (block)))
 
+============================
+binary operator method names
+============================
+
+def !=(other)
+  self.n != other.n
+end
+
+def ==(other)
+  true
+end
+
+def <=>(other)
+  0
+end
+
+---
+
+(program
+  (method
+    name: (operator)
+    parameters: (method_parameters
+      (identifier))
+    body: (body_statement
+      (binary
+        left: (call
+          receiver: (self)
+          method: (identifier))
+        right: (call
+          receiver: (identifier)
+          method: (identifier)))))
+  (method
+    name: (operator)
+    parameters: (method_parameters
+      (identifier))
+    body: (body_statement
+      (true)))
+  (method
+    name: (operator)
+    parameters: (method_parameters
+      (identifier))
+    body: (body_statement
+      (integer))))
+
 ===========================
 unary operator method names
 ===========================

test/corpus/expressions.txt

@@ -613,6 +613,33 @@ a...b
     (identifier)
     (identifier)))
 
+=================================
+dot call syntax
+=================================
+
+x.(123)
+x.()
+
+---
+
+(program
+  (call
+    receiver: (identifier)
+    arguments: (argument_list
+      (integer)))
+  (call
+    receiver: (identifier)
+    arguments: (argument_list)))
+
+===================================================
+dot call syntax rejects a second argument list
+:error
+===================================================
+
+x.(123)(456)
+
+---
+
 ===========================================
 newline after range operator continues range
 ===========================================

test/corpus/literals.txt

@@ -1531,6 +1531,25 @@ un-terminated heredocs
     (heredoc_content)
     (heredoc_end)))
 
+==========================================
+un-terminated heredoc identifier does not crash the scanner
+==========================================
+
+<<~"BASH
+  if the string inside is too short it doesn't crash
+  but I haven't found exactly how many chars is the problem
+
+  if the string inside is too short it doesn't crash
+  but I haven't found exactly how many chars is the problem
+
+  it needs this line
+BASH
+
+---
+
+(program
+  (heredoc_beginning))
+
 =================================
 no interpolation or escape sequences in single quoted heredoc
 =================================