Escape some variables in llvm.mk
Escape some variables in llvm.mk

The important one is $(MAKE).  make handles recipes containing the
literal string "$(MAKE)" specially, so it is important to make sure it
isn't evaluated until recipe invocation time.

GBGamer/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,GBGamer/rust,graydon/rust,GBGamer/rust,graydon/rust,GBGamer/rust,graydon/rust,GBGamer/rust,graydon/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,aidancully/rust,GBGamer/rust