Fix sipush return type annotation

(Source: https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html)

Nothing appears to use the annotation at the moment, so it cause any ill
behaviour and can't be tested, but in case it becomes used in the future
we might as well correct it.

Author: smowton

src/java_bytecode/bytecode_info.cpp

@@ -212,7 +212,7 @@ struct bytecode_infot const bytecode_info[]=
 { "return",         0xb1, ' ', 0, 0, ' ' }, // → [empty]; return void from method  NOLINT(*)
 { "saload",         0x35, ' ', 2, 1, 's' }, // arrayref, index → value; load short from array  NOLINT(*)
 { "sastore",        0x56, ' ', 3, 0, 's' }, // arrayref, index, value →; store short to array  NOLINT(*)
-{ "sipush",         0x11, 's', 0, 1, 's' }, // → value; push a short onto the stack  NOLINT(*)
+{ "sipush",         0x11, 's', 0, 1, 'i' }, // → value; push a short onto the stack as an integer value  NOLINT(*)
 { "swap",           0x5f, ' ', 2, 2, ' ' }, // value2, value1 → value1, value2; swaps two top words on the stack (note that value1 and value2 must not be double or long)  NOLINT(*)
 { "tableswitch",    0xaa, 'T', 1, 0, ' ' }, // index →; continue execution from an address in the table at offset index  NOLINT(*)
 { "breakpoint",     0xca, ' ', 0, 0, ' ' }, // ; reserved for breakpoints in Java debuggers; should not appear in any class file  NOLINT(*)