rounding issue in static assert

thrift.codegen.idlgen

static assert(structIdlString!WithDefaults ==
`struct WithDefaults {
-1: string a = "asdf",
-2: double b = 3.1415,
1: WithoutMeta c =

,
}
`);

This assert fails for me, because struct contains double b = 3.1414999...999
I suggest replace 3.1415 with 1.0e+20
This value is free from rounding issues.

FYI
thrift.internal.ctfe contains similar unit test, but it is not use strict match:
static assert(ctfeToString(3.1415).startsWith("3.141"));

Create pull request: https://github.com/apache/thrift/pull/720