ValueTuple.Equals is not folded for constant strings

```cs
bool Test(string a) => (a, "123") == ("44", "5555");
```
Expected:
```asm
xor eax, eax
ret
```
Actual:
```asm
mov rax, 0x1E5C96450C8 ; '44'
cmp rdx, rax
je SHORT G_M49591_IG08
test rdx, rdx
je SHORT G_M49591_IG06
cmp dword ptr [rdx+0x08], 2
jne SHORT G_M49591_IG06
cmp dword ptr [rdx+0x0C], 0x340034
je SHORT G_M49591_IG08
G_M49591_IG06:
xor eax, eax
ret
G_M49591_IG08:
xor eax, eax
ret
```