MIR Parser: Extract the code that parses MBB references into a new method. NFC.

This commit extracts the code that's used by the class 'MIRParserImpl' to parse
the machine basic block references into a new method named 'parseMBBReference'.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243572 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed