RISC-V: Minimal build failed after JDK-8316592

Error log for minimal build:

```
ERROR: Build failed for target 'all' in configuration 'linux-riscv64-minimal-fastdebug' (exit code 2)
Stopping javac server

=== Output from failing command(s) repeated here ===
* For target hotspot_variant-minimal_libjvm_objs_macroAssembler_riscv.o:
/home/jiangfeilong/workspace/jdk/src/hotspot/cpu/riscv/macroAssembler_riscv.cpp: In member function 'void MacroAssembler::wide_madd(Register, Register, Register, Register, Register, Register)':
/home/jiangfeilong/workspace/jdk/src/hotspot/cpu/riscv/macroAssembler_riscv.cpp:2064:3: error: 'cad' was not declared in this scope
 2064 | cad(sum_lo, sum_lo, tmp1, tmp1); // Add tmp1 to sum_lo with carry output to tmp1
      | ^~~
/home/jiangfeilong/workspace/jdk/src/hotspot/cpu/riscv/macroAssembler_riscv.cpp:2065:3: error: 'adc' was not declared in this scope; did you mean 'add'?
 2065 | adc(sum_hi, sum_hi, tmp2, tmp1); // Add tmp2 with carry to sum_hi
      | ^~~
      | add

* All command lines available in /home/jiangfeilong/workspace/jdk/build/linux-riscv64-minimal-fastdebug/make-support/failure-logs.
=== End of repeated output ===
```

The root cause is that `cad` and `adc` are defined under `COMPILER2` macro but new methods `wide_mul` and `wide_madd` are not.