Support .offset and .length for calldata bytes and string arrays.

test/libsolidity/semanticTests/inlineAssembly/calldata_array_read.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f(uint[2][] calldata x) public returns (uint o, uint l, uint s) {
+        assembly { l := x.length o := x.offset }
+        uint[2] calldata t = x[1];
+        // statically-sized arrays only use one slot, so we read directly.
+        assembly { s := t }
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// f(uint256[2][]): 0x20, 2, 1, 2, 3, 4 -> 0x44, 2, 0x84