Remove opens in bootstrap translation

[myreen]

I was surprised that there are some very obvious opens in bootstrap translation:

cakeml/compiler/bootstrap/translation/compiler64ProgScript.sml

Lines 4 to 14 in f46cb7a

	Theory compiler64Prog[no_sig_docs]
	Ancestors
	mipsProg compiler export ml_translator basis_ffi[qualified]
	Libs
	preamble ml_translatorLib cfLib basis
	open preamble
	mipsProgTheory compilerTheory
	exportTheory
	ml_translatorLib ml_translatorTheory
	open cfLib basis

cakeml/compiler/bootstrap/translation/arm8ProgScript.sml

Lines 4 to 15 in f46cb7a

	Theory arm8Prog[no_sig_docs]
	Ancestors
	arm8_target arm8 evaluate ml_translator x64Prog
	Libs
	preamble ml_translatorLib inliningLib
	open preamble;
	open evaluateTheory
	open ml_translatorLib ml_translatorTheory;
	open x64ProgTheory
	open arm8_targetTheory arm8Theory;
	open inliningLib;