Check that symbol table is populate correctly

This commit adds tests for
- compound declarations `(x,y,z)` which declares `x`, `y` and `z`
- locality of arguments of functions

tests/test_ASTSymbolTableBuilder.cpp

@@ -21,6 +21,44 @@ N n = 2;
     ASTSymbolTableBuilder{*ast};
   }
 
+  SECTION("Populate symbol table")
+  {
+    std::string_view data = R"(
+B b;
+N n;
+Z z;
+R x;
+R*Z*N*B (c0,c1,c2,c3);
+let f: R*Z*B->R, (x,n,z) -> x+n;
+)";
+
+    string_input input{data, "test.pgs"};
+    auto ast = ASTBuilder::build(input);
+
+    ASTSymbolTableBuilder{*ast};
+
+    auto root_st = ast->m_symbol_table;
+
+    std::stringstream st_output;
+    st_output << '\n' << *root_st;
+
+    std::stringstream expected_output;
+    expected_output << '\n'
+                    << "-- Symbol table state -- parent : " << static_cast<SymbolTable*>(nullptr) << '\n'
+                    << " b: --\n"
+                    << " n: --\n"
+                    << " z: --\n"
+                    << " x: --\n"
+                    << " c0: --\n"
+                    << " c1: --\n"
+                    << " c2: --\n"
+                    << " c3: --\n"
+                    << " f: 0\n"
+                    << "------------------------\n";
+
+    REQUIRE(st_output.str() == expected_output.str());
+  }
+
   SECTION("errors")
   {
     SECTION("Undeclared symbol")