Add more tests

Author: matheusaaguiar

test/libsolidity/syntaxTests/contractBaseLocation/layout_already_specified_in_ancestor_contract_.sol

@@ -0,0 +1,8 @@
+contract A layout at 0x1234 {}
+
+contract B is A {}
+
+contract C is B layout at 0xABCD {}
+// ----
+// TypeError 8894: (32-50): Storage base location can only be specified in the most derived contract.
+// TypeError 8894: (52-87): Storage base location can only be specified in the most derived contract.

test/libsolidity/syntaxTests/contractBaseLocation/layout_not_specified_in_most_derived_contract_copy.sol

@@ -0,0 +1,8 @@
+contract A layout at 0x1234 {}
+
+contract B is A {}
+
+contract C is B {}
+// ----
+// TypeError 8894: (32-50): Storage base location can only be specified in the most derived contract.
+// TypeError 8894: (52-70): Storage base location can only be specified in the most derived contract.

test/libsolidity/syntaxTests/contractBaseLocation/layout_specified_by_expression_not_pure.sol

@@ -0,0 +1,5 @@
+function f(uint x) returns (uint) { return x + 1; }
+contract A layout at f(2) {}
+// ----
+// TypeError 1139: (73-77): The contract base location must be an expression that can be evaluated at compilation time.
+// TypeError 6396: (73-77): Only number literals are accepted in the expression specifying the contract base storage location.