Make ParseIdentifier a public method instead of private.

The MCAsmParser interface defines ParseIdentifier is public. There's no reason
whatsoever for AsmParser (which implements the MCAsmParser interface) to hide
this method.

This is all part of a bigger scheme. Several asm parsing "extensions" use the
main parser properly through the MCAsmParser interface. However,
GenericAsmParser has much more exclusive access and uses implementation details
from the concrete implementation - AsmParser, in which it is also declared as
a friend. This makes for overly coupled code, and even makes it hard to split
GenericAsmParser into a separate file. There's no reason why GenericAsmParser
shouldn't be able to access AsmParser through an abstract interface, as long
as it's actually registered as an extension.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172276 91177308-0d34-0410-b5e6-96231b3b80d8
Stop hiding the interface-exposed EatToEndOfStatement (see r172276).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172277 91177308-0d34-0410-b5e6-96231b3b80d8
Precompute some information about register costs.

Remember the minimum cost of the registers in an allocation order and
the number of registers at the end of the allocation order that have the
same cost per use.

This information can be used to limit the search space for
RAGreedy::tryEvict() when looking for a cheaper register.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172280 91177308-0d34-0410-b5e6-96231b3b80d8
Limit the search space in RAGreedy::tryEvict().

When tryEvict() is looking for a cheaper register in the allocation
order, skip the tail of too expensive registers when possible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172281 91177308-0d34-0410-b5e6-96231b3b80d8