imul2 function
An alternate implementation of imul
Appears to perform considerably better in AOT binaries.
Implementation
@pragma('vm:prefer-inline')
int imul2(int a, int b) {
var result = (a & 0x003fffff) * b;
if (a & 0xffc00000 != 0) result += (a & 0xffc00000) * b | 0;
return result.toSigned(32);
}