v: parser: rv64: asm: Support for base+displacement addressing

vlib/v/parser/parser.v

@@ -1313,8 +1313,15 @@ fn (mut p Parser) asm_stmt(is_top_level bool) ast.AsmStmt {
 										pos: number_lit.pos
 									}
 								} else {
-									args << ast.IntegerLiteral{
-										...number_lit
+									if arch == .rv64 {
+										if (p.tok.kind == .lpar) && (p.peek_token(2).kind == .rpar) {
+											mut addressing := p.asm_addressing_rv64()
+											args << addressing
+										}
+									} else {
+										args << ast.IntegerLiteral{
+											...number_lit
+										}
 									}
 								}
 							}
@@ -1567,6 +1574,23 @@ fn (mut p Parser) reg_or_alias() ast.AsmArg {
 // 	}
 // }
 
+fn (mut p Parser) asm_addressing_rv64() ast.AsmAddressing {
+	pos := p.tok.pos()
+	p.check(.lpar)
+	displacement := ast.AsmArg(ast.AsmDisp{
+		val: p.peek_token(-2).lit
+		pos: p.tok.pos()
+	})
+	base := p.reg_or_alias()
+	p.check(.rpar)
+	return ast.AsmAddressing{
+		mode: .base_plus_displacement
+		base: base
+		displacement: displacement
+		pos: pos.extend(p.prev_tok.pos())
+	}
+}
+
 fn (mut p Parser) asm_addressing() ast.AsmAddressing {
 	pos := p.tok.pos()
 	p.check(.lsbr)