Proposal: log binary data for Solidity

The program_id is not needed on "Program return data: " because it
always preceeded by the program invoke message, so no need to repeat
the program id. Also rename this to "Program return: " since "data"
is redundant.

sdk/program/src/log.rs

@@ -85,6 +85,23 @@ extern "C" {
     fn sol_log_64_(arg1: u64, arg2: u64, arg3: u64, arg4: u64, arg5: u64);
 }
 
+/// Print some slices as base64
+///
+/// @param data - The slices to print
+pub fn sol_log_data(data: &[&[u8]]) {
+    #[cfg(target_arch = "bpf")]
+    {
+        extern "C" {
+            fn sol_log_data(data: *const u8, data_len: u64);
+        }
+
+        unsafe { sol_log_data(data as *const _ as *const u8, data.len() as u64) };
+    }
+
+    #[cfg(not(target_arch = "bpf"))]
+    crate::program_stubs::sol_log_data(data);
+}
+
 /// Print the hexadecimal representation of a slice
 ///
 /// @param slice - The array to print