RISCV: Make analysis function set mnemonic field to enable ROP search (#5952)

* Make analysis function set mnemonic field to enablre ROP search
* Add tests

Author: moste00

librz/arch/p/analysis/analysis_riscv_cs.c

@@ -781,7 +781,7 @@ int analyze_op(RzAnalysis *analysis, RzAnalysisOp *op, ut64 addr, const ut8 *buf
 		ctx->omode = mode;
 		ctx->obits = analysis->bits;
 	}
-
+	analysis->pcalign = 2;
 	op->addr = addr;
 	if (len < 2) {
 		return -1;
@@ -1911,6 +1911,10 @@ int analyze_op(RzAnalysis *analysis, RzAnalysisOp *op, ut64 addr, const ut8 *buf
 	}
 beach:
 	if (insn) {
+		if (mask & RZ_ANALYSIS_OP_MASK_DISASM) {
+			op->mnemonic = rz_str_newf("%s%s%s", insn->mnemonic, insn->op_str[0] ? " " : "", rz_str_get(insn->op_str));
+		}
+
 		set_op_sign(op, insn);
 		set_op_data_size(op, insn);
 		set_op_val(op, insn);

librz/core/rop.c

@@ -1539,6 +1539,8 @@ static void set_increment_based_on_arch(const RzCore *core, const char *arch, in
 		*increment = rz_config_get_i(core->config, "asm.bits") == 16 ? 2 : 4;
 	} else if (RZ_STR_EQ(arch, "avr")) { // AVR is halfword aligned.
 		*increment = 2;
+	} else if (RZ_STR_EQ(arch, "riscv")) {
+		*increment = core->analysis->pcalign;
 	}
 }