Adds parsing sub-directory in syntaxTests and moves two example tests from SolidityParser.cpp to test contracts.

test/libsolidity/syntaxTests/parsing/missing_variable_name_in_declaration.sol

@@ -0,0 +1,5 @@
+contract test {
+    uint256 ;
+}
+// ----
+// ParserError: Expected identifier, got 'Semicolon'

test/libsolidity/syntaxTests/parsing/smoke_test.sol

@@ -0,0 +1,4 @@
+contract test {
+    uint256 stateVariable1;
+}
+// ----