Line ending policies were changed in the parent, dccebddb3b80. To make
it easier to resolve downstream merge conflicts after line-ending
policies are adjusted this is a separate whitespace-only commit. If you
have merge conflicts as a result, you can simply `git add --renormalize
-u && git merge --continue` or `git add --renormalize -u && git rebase
--continue` - depending on your workflow.
Rework `IntrinsicEmitter::EmitIntrinsicToBuiltinMap` for improved
peformance as well as refactor the code.
Performance:
- Current generated code does a linear search on the TargetPrefix,
followed by a binary search on the builtin names for that
target's builtins.
- Improve the performance of this code in 2 ways:
(a) Use binary search on the target prefix to lookup the builtin
table for the target.
(b) Improve the (common) case of when all builtins for a target
share a common prefix. Check this common prefix first, and
then do the binary search in the builtin table using the builtin
name with the common prefix removed. This should help
both data size (by creating a smaller static string table) and
runtime (by reducing the cost of binary search on smaller
strings).
Refactor:
- Use range based for loops for iterating over maps.
- Use formatv() and C++ raw string literals to simplify the emission
code.
- Change the generated `getIntrinsicForClangBuiltin` and
`getIntrinsicForMSBuiltin` to take a `StringRef` instead of
`const char *` for the prefix.
