Support local suspend functions

Treat them like lambdas. This means:
1) Like local suspend lambdas, which become "non-suspend" after creating
jvmSuspendView, they do this as well
2) They both are generated with the same codegen.
3) They are treated differently only on front-end side.
 #KT-20364: Fixed

core/descriptors/src/org/jetbrains/kotlin/descriptors/FunctionDescriptor.java

@@ -144,6 +144,9 @@ public interface FunctionDescriptor extends CallableMemberDescriptor {
         @NotNull
         CopyBuilder<D> setDropOriginalInContainingParts();
 
+        @NotNull
+        CopyBuilder<D> setDropSuspend();
+
         @NotNull
         CopyBuilder<D> setHiddenToOvercomeSignatureClash();
 

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/FunctionDescriptorImpl.java

@@ -372,6 +372,7 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
         private Map<UserDataKey<?>, Object> userDataMap = new LinkedHashMap<UserDataKey<?>, Object>();
         private Boolean newHasSynthesizedParameterNames = null;
         protected boolean justForTypeSubstitution = false;
+        private boolean dropSuspend = false;
 
         public CopyConfiguration(
                 @NotNull TypeSubstitution substitution,
@@ -500,6 +501,13 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
             return this;
         }
 
+        @Override
+        @NotNull
+        public CopyConfiguration setDropSuspend() {
+            this.dropSuspend = true;
+            return this;
+        }
+
         @Override
         @NotNull
         public CopyConfiguration setHiddenToOvercomeSignatureClash() {
@@ -664,7 +672,11 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
         substitutedDescriptor.setExternal(isExternal);
         substitutedDescriptor.setInline(isInline);
         substitutedDescriptor.setTailrec(isTailrec);
-        substitutedDescriptor.setSuspend(isSuspend);
+        if (configuration.dropSuspend) {
+            substitutedDescriptor.setSuspend(false);
+        } else {
+            substitutedDescriptor.setSuspend(isSuspend);
+        }
         substitutedDescriptor.setExpect(isExpect);
         substitutedDescriptor.setActual(isActual);
         substitutedDescriptor.setHasStableParameterNames(hasStableParameterNames);

core/descriptors/src/org/jetbrains/kotlin/types/error/ErrorSimpleFunctionDescriptorImpl.java

@@ -168,6 +168,12 @@ public class ErrorSimpleFunctionDescriptorImpl extends SimpleFunctionDescriptorI
                 return this;
             }
 
+            @NotNull
+            @Override
+            public CopyBuilder<SimpleFunctionDescriptor> setDropSuspend() {
+                return this;
+            }
+
             @NotNull
             @Override
             public CopyBuilder<SimpleFunctionDescriptor> setHiddenToOvercomeSignatureClash() {