[ThinLTO] Allow importing of functions with var args

Summary:
Follow up to D54270, which allowed importing of var args functions
unless they called va_start. As pointed out in the post-commit comments
on that patch, the inliner can handle functions that call va_start in
certain situations as well. Go ahead and enable importing of all var
args functions. Measurements on a large binary show that this increases
imports and binary size by an insignificant amount.

Reviewers: davidxl

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D54607

llvm-svn: 348068
diff --git a/llvm/test/Bitcode/thinlto-function-summary.ll b/llvm/test/Bitcode/thinlto-function-summary.ll
index 8563d12..be7e974 100644
--- a/llvm/test/Bitcode/thinlto-function-summary.ll
+++ b/llvm/test/Bitcode/thinlto-function-summary.ll
@@ -22,10 +22,7 @@
 ; BC-NEXT: <PERMODULE {{.*}} op0=1 op1=0
 ; BC-NEXT: <PERMODULE {{.*}} op0=2 op1=0
 ; BC-NEXT: <PERMODULE {{.*}} op0=3 op1=7
-; Summary for @variadic has flags (op3) = 16 since non-inlinable owing to
-; va_start call.
-; flag is set due to va_start call.
-; BC-NEXT: <PERMODULE {{.*}} op0=4 op1=0 op2=4 op3=16
+; BC-NEXT: <PERMODULE {{.*}} op0=4 op1=0 op2=4 op3=0
 ; BC-NEXT: <ALIAS {{.*}} op0=6 op1=0 op2=3
 ; BC-NEXT: </GLOBALVAL_SUMMARY_BLOCK
 ; BC: <STRTAB_BLOCK