Stop generating _d_eh_personality with -betterC

Closes #3479

Author: kubo39

gen/funcgenstate.cpp

@@ -9,6 +9,7 @@
 
 #include "gen/funcgenstate.h"
 
+#include "dmd/globals.h"
 #include "dmd/identifier.h"
 #include "gen/llvm.h"
 #include "gen/llvmhelpers.h"
@@ -118,6 +119,7 @@ llvm::CallSite FuncGenState::callOrInvoke(llvm::Value *callee,
   // Intrinsics don't support invoking and 'nounwind' functions don't need it.
   const bool doesNotThrow =
       isNothrow ||
+      global.params.checkAction == CHECKACTION_C ||
       (calleeFn && (calleeFn->isIntrinsic() || calleeFn->doesNotThrow()));
 
   // calls inside a funclet must be annotated with its value

tests/compilable/gh3479.d

@@ -0,0 +1,12 @@
+// RUN: %ldc -betterC -run %s
+
+extern (C) int main()
+{
+    int a = 5;
+    scope(exit) a = 6;
+    create(0, 1, "2");
+    return 0;
+}
+
+void create(uint a, uint b, string c) {
+}