[Inlining] Make shouldBeDeferred static (NFC)

Summary:
This patch makes shouldBeDeferred static because it is called only
from shouldInline in the same .cpp file.

Reviewers: davidxl, mtrofin

Reviewed By: mtrofin

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79750
diff --git a/llvm/lib/Analysis/InlineAdvisor.cpp b/llvm/lib/Analysis/InlineAdvisor.cpp
index eae0d24..e9d4f7e 100644
--- a/llvm/lib/Analysis/InlineAdvisor.cpp
+++ b/llvm/lib/Analysis/InlineAdvisor.cpp
@@ -51,9 +51,9 @@
 /// estimated inline cost associated with callsite \p CB.
 /// \p TotalSecondaryCost will be set to the estimated cost of inlining the
 /// caller if \p CB is suppressed for inlining.
-bool llvm::shouldBeDeferred(
-    Function *Caller, InlineCost IC, int &TotalSecondaryCost,
-    function_ref<InlineCost(CallBase &CB)> GetInlineCost) {
+static bool
+shouldBeDeferred(Function *Caller, InlineCost IC, int &TotalSecondaryCost,
+                 function_ref<InlineCost(CallBase &CB)> GetInlineCost) {
   // For now we only handle local or inline functions.
   if (!Caller->hasLocalLinkage() && !Caller->hasLinkOnceODRLinkage())
     return false;