Reintroduce the InlineHint function attribute.

This time it's for real! I am going to hook this up in the frontends as well.

The inliner has some experimental heuristics for dealing with the inline hint.
When given a -respect-inlinehint option, functions marked with the inline
keyword are given a threshold just above the default for -O3.

We need some experiments to determine if that is the right thing to do.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95466 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/vim/llvm.vim b/utils/vim/llvm.vim
index 48a4c68..6e4a207 100644
--- a/utils/vim/llvm.vim
+++ b/utils/vim/llvm.vim
@@ -51,7 +51,7 @@
 syn keyword llvmKeyword x86_stdcallcc x86_fastcallcc
 syn keyword llvmKeyword signext zeroext inreg sret nounwind noreturn
 syn keyword llvmKeyword nocapture byval nest readnone readonly noalias
-syn keyword llvmKeyword noinline alwaysinline optsize ssp sspreq
+syn keyword llvmKeyword inlinehint noinline alwaysinline optsize ssp sspreq
 syn keyword llvmKeyword noredzone noimplicitfloat naked
 syn keyword llvmKeyword module asm align tail to
 syn keyword llvmKeyword addrspace section alias sideeffect c gc