[Compiler] Support dynamically constructed bitfields

[water111]

The compiler will now accept bifield defintions like

(new 'static 'test-bf-type7 :f1 #x12 :f2 (+ #x10 3 #x100) :f3 12.3433 :f4 ((lambda () 1)))

It works just like GOAL and will combine all fields known at compile time, then or in the others:

  [0x10031] mov rax, 0x20A2BF14000012              mov-ic igpr-11, 9186140812738578
  [0x1003b] mov ecx, 0x10                          mov-ic igpr-13, 16
  [0x10040] mov edx, 0x03                          mov-ic igpr-14, 3
  [0x10045] add rcx, rdx                           addi igpr-12, igpr-14
  [0x10048] mov edx, 0x100                         mov-ic igpr-15, 256
  [0x1004d] add rcx, rdx                           addi igpr-12, igpr-15
  [0x10050] shl rcx, 0x39                          shl igpr-12, 57
  [0x10054] shr rcx, 0x29                          shr igpr-12, 41
  [0x10058] or rax, rcx                            or igpr-11, igpr-12
  [0x1005b] mov ecx, 0x01                          mov-ic igpr-16, 1
  [0x10060] shl rcx, 0x3F                          shl igpr-16, 63
  [0x10064] shr rcx, 0x08                          shr igpr-16, 8
  [0x10068] or rax, rcx                            or igpr-11, igpr-16

[coveralls]

Pull Request Test Coverage Report for Build 739254118

• 49 of 56 (87.5%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.02%) to 69.241%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
goalc/compiler/compilation/Type.cpp	1	2	50.0%
goalc/compiler/compilation/Static.cpp	46	52	88.46%

Totals
Change from base Build 738974521:	0.02%
Covered Lines:	33436
Relevant Lines:	48289

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💛 - Coveralls