C#: Fix IR consistency errors

We were creating a `TranslatedFunction` even for functions that were not from source code, but then telling the IR package that those functions didn't have IR. This resulted in having prologue/epilogue instructions (e.g. `EnterFunction`, `ExitFunction`) with no enclosing `IRFunction`.

Author: Dave Bartolomeo

csharp/ql/src/experimental/ir/implementation/raw/internal/IRConstruction.qll

@@ -25,10 +25,7 @@ import Cached
 cached
 private module Cached {
   cached
-  predicate functionHasIR(Callable callable) {
-    exists(getTranslatedFunction(callable)) and
-    callable.fromSource()
-  }
+  predicate functionHasIR(Callable callable) { exists(getTranslatedFunction(callable)) }
 
   cached
   newtype TInstruction =

csharp/ql/src/experimental/ir/implementation/raw/internal/TranslatedElement.qll

@@ -117,6 +117,7 @@ private predicate ignoreExpr(Expr expr) {
 private predicate translateFunction(Callable callable) {
   // not isInvalidFunction(callable)
   exists(callable.getEntryPoint()) and
+  callable.fromSource() and
   exists(IRConfiguration config | config.shouldCreateIRForFunction(callable))
 }
 

csharp/ql/test/experimental/ir/ir/raw_ir_consistency.expected

@@ -21,12 +21,6 @@ notMarkedAsConflated
 wronglyMarkedAsConflated
 invalidOverlap
 nonUniqueEnclosingIRFunction
-| indexers.cs:3:18:3:24 | AliasedDefinition: MyClass | Instruction 'AliasedDefinition: MyClass' has 0 results for `getEnclosingIRFunction()` in function '$@'. | file://:0:0:0:0 | <Missing IRFunction> | <Missing IRFunction> |
-| indexers.cs:3:18:3:24 | AliasedUse: MyClass | Instruction 'AliasedUse: MyClass' has 0 results for `getEnclosingIRFunction()` in function '$@'. | file://:0:0:0:0 | <Missing IRFunction> | <Missing IRFunction> |
-| indexers.cs:3:18:3:24 | EnterFunction: MyClass | Instruction 'EnterFunction: MyClass' has 0 results for `getEnclosingIRFunction()` in function '$@'. | file://:0:0:0:0 | <Missing IRFunction> | <Missing IRFunction> |
-| indexers.cs:3:18:3:24 | ExitFunction: MyClass | Instruction 'ExitFunction: MyClass' has 0 results for `getEnclosingIRFunction()` in function '$@'. | file://:0:0:0:0 | <Missing IRFunction> | <Missing IRFunction> |
-| indexers.cs:3:18:3:24 | InitializeThis: MyClass | Instruction 'InitializeThis: MyClass' has 0 results for `getEnclosingIRFunction()` in function '$@'. | file://:0:0:0:0 | <Missing IRFunction> | <Missing IRFunction> |
-| indexers.cs:3:18:3:24 | ReturnVoid: MyClass | Instruction 'ReturnVoid: MyClass' has 0 results for `getEnclosingIRFunction()` in function '$@'. | file://:0:0:0:0 | <Missing IRFunction> | <Missing IRFunction> |
 missingCanonicalLanguageType
 multipleCanonicalLanguageTypes
 missingIRType