fix Issue 11505 - Bad error message: "opAssign [...] is annotated with @disable"
fix Issue 11479 - template members ignore private attribute in ddoc
vcbuild: make output of real nan/inf consistent with dmc compiled dmd
fix Issue 11627 - [CTFE] cannot cast dchar to char at compile time on AA assignment
fix Issue 11614 - Error: this for _expand_field_0 needs to be type Tuple not type Foo

Even if a variable has no valid context, it would be either:

1. a part of compile time evaluated expression, which is used as unreal context.
    enum x = Type.fieldvar.sizeof;
    // It's legitimate expression so fieldvar is not evaluated
    // in runtime.

2. or an invalid field access without valid 'this', in runtime evaluated expression.
    int y = Type.fieldvar;
    // It's invalid expression so fieldvar access has no valid 'this'.

For the case #2, it will be an error by `checkRightThis` later. Therefore `getRightThis` should not make it an error.
Merge pull request #2804 from 9rnsr/fix11505

[REG2.064] Issue 11505 - Bad error message: "opAssign [...] is annotated with @disable"
Merge pull request #2897 from 9rnsr/fix11614

[REG2.064] Issue 11614 - Error: this for _expand_field_0 needs to be type Tuple not type Foo
Merge pull request #2892 from 9rnsr/fix11627

Issue 11627 - [CTFE] cannot cast dchar to char at compile time on AA assignment
Merge pull request #2902 from rainers/vc_pass_tests

vcbuild: make output of real nan/inf consistent with dmc compiled dmd
Merge pull request #2900 from 9rnsr/fix11479

Issue 11479 - template members ignore private attribute in ddoc