prefix boolean variables with is to match Java conventions

Author: madsodgaard

Sources/JExtractSwiftLib/FFM/FFMSwift2JavaGenerator+JavaTranslation.swift

@@ -126,6 +126,7 @@ extension FFMSwift2JavaGenerator {
       let loweredSignature = try lowering.lowerFunctionSignature(decl.functionSignature)
 
       // Name.
+      let returnsBoolean = decl.functionSignature.result.type.asNominalTypeDeclaration?.knownTypeKind == .bool
       let javaName = switch decl.apiKind {
       case .getter: decl.javaGetterName
       case .setter: decl.javaSetterName

Sources/JExtractSwiftLib/ImportedDecls.swift

@@ -91,7 +91,7 @@ public final class ImportedFunc: ImportedDecl, CustomStringConvertible {
     }
     return false
   }
-  
+
   /// If this function/method is member of a class/struct/protocol,
   /// this will contain that declaration's imported name.
   ///

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+JavaTranslation.swift

@@ -38,6 +38,7 @@ extension JNISwift2JavaGenerator {
       let parentName = decl.parentType?.asNominalType?.nominalTypeDecl.qualifiedName ?? swiftModuleName
 
       // Name.
+      let returnsBoolean = translatedFunctionSignature.resultType == .boolean
       let javaName = switch decl.apiKind {
       case .getter: decl.javaGetterName
       case .setter: decl.javaSetterName