Update existing tests.

test/cmdlineTests/recovery_ast_empty_contract/err

@@ -1,4 +1,4 @@
-Error: Expected pragma, import directive or contract/interface/library/struct/enum/function definition.
+Error: Expected pragma, import directive or contract/interface/library/struct/enum/constant/function definition.
  --> recovery_ast_empty_contract/input.sol:3:1:
   |
 3 | c

test/libsolidity/errorRecoveryTests/wrong_compiler_recovers_2.sol

@@ -1,4 +1,6 @@
 pragma solidity ^99.99.0;
 this is surely invalid
 // ----
-// ParserError 7858: (26-30): Expected pragma, import directive or contract/interface/library/struct/enum/function definition.
+// ParserError 6635: (31-33): Expected identifier but got 'is'
+// ParserError 6635: (34-40): Expected ';' but got identifier
+// ParserError 6635: (49-49): Expected ';' but got end of source

test/libsolidity/syntaxTests/array/length/array_length_cannot_be_constant_function_parameter.sol

@@ -4,6 +4,6 @@ contract C {
     }
 }
 // ----
-// DeclarationError 1788: (28-45): The "constant" keyword can only be used for state variables.
+// DeclarationError 1788: (28-45): The "constant" keyword can only be used for state variables or variables at file level.
 // TypeError 5462: (69-72): Invalid array length, expected integer literal or constant expression.
 // TypeError 6651: (64-75): Data location must be "storage", "memory" or "calldata" for variable, but none was given.

test/libsolidity/syntaxTests/freeFunctions/free_constructor.sol

@@ -1,3 +1,3 @@
 constructor() {}
 // ----
-// ParserError 7858: (0-11): Expected pragma, import directive or contract/interface/library/struct/enum/function definition.
+// ParserError 7858: (0-11): Expected pragma, import directive or contract/interface/library/struct/enum/constant/function definition.

test/libsolidity/syntaxTests/freeFunctions/free_fallback.sol

@@ -1,3 +1,3 @@
 fallback(){}
 // ----
-// ParserError 7858: (0-8): Expected pragma, import directive or contract/interface/library/struct/enum/function definition.
+// ParserError 7858: (0-8): Expected pragma, import directive or contract/interface/library/struct/enum/constant/function definition.

test/libsolidity/syntaxTests/freeFunctions/free_receive.sol

@@ -1,3 +1,3 @@
 receive() {}
 // ----
-// ParserError 7858: (0-7): Expected pragma, import directive or contract/interface/library/struct/enum/function definition.
+// ParserError 7858: (0-7): Expected pragma, import directive or contract/interface/library/struct/enum/constant/function definition.

test/libsolidity/syntaxTests/nameAndTypeResolution/105_constant_input_parameter.sol

@@ -2,4 +2,4 @@ contract test {
     function f(uint[] memory constant a) public { }
 }
 // ----
-// DeclarationError 1788: (31-55): The "constant" keyword can only be used for state variables.
+// DeclarationError 1788: (31-55): The "constant" keyword can only be used for state variables or variables at file level.

test/libsolidity/syntaxTests/natspec/docstring_variable.sol

@@ -11,4 +11,4 @@ contract C {
     }
 }
 // ----
-// ParserError 2837: (290-295): Only state variables can have a docstring.
+// ParserError 2837: (290-295): Only state variables or file-level variables can have a docstring.

test/libsolidity/syntaxTests/parsing/location_specifiers_for_params.sol

@@ -2,4 +2,4 @@ contract Foo {
     function f(uint[] storage constant x, uint[] memory y) internal { }
 }
 // ----
-// DeclarationError 1788: (30-55): The "constant" keyword can only be used for state variables.
+// DeclarationError 1788: (30-55): The "constant" keyword can only be used for state variables or variables at file level.

test/libsolidity/syntaxTests/unexpected.sol

@@ -1,3 +1,3 @@
 unexpected
 // ----
-// ParserError 7858: (0-10): Expected pragma, import directive or contract/interface/library/struct/enum/function definition.
+// ParserError 7858: (0-10): Expected pragma, import directive or contract/interface/library/struct/enum/constant/function definition.