Removed automatic '--relax' hack for compiles on Atmega2560 MCU (#749)

This removes the --relax option, potentially producing slightly bigger code for the atmega2560. On the longer term, the AVR core should just add this option for all boards, but this is not currently the case yet because removing --relax also works around a gcc miscompilation (see arduino/ArduinoCore-avr#339).

Close: #639

legacy/builder/phases/linker.go

@@ -57,13 +57,11 @@ func (s *Linker) Run(ctx *types.Context) error {
 }
 
 func link(ctx *types.Context, objectFiles paths.PathList, coreDotARelPath *paths.Path, coreArchiveFilePath *paths.Path, buildProperties *properties.Map) error {
-	optRelax := addRelaxTrickIfATMEGA2560(buildProperties)
-
 	quotedObjectFiles := utils.Map(objectFiles.AsStrings(), wrapWithDoubleQuotes)
 	objectFileList := strings.Join(quotedObjectFiles, constants.SPACE)
 
 	properties := buildProperties.Clone()
-	properties.Set(constants.BUILD_PROPERTIES_COMPILER_C_ELF_FLAGS, properties.Get(constants.BUILD_PROPERTIES_COMPILER_C_ELF_FLAGS)+optRelax)
+	properties.Set(constants.BUILD_PROPERTIES_COMPILER_C_ELF_FLAGS, properties.Get(constants.BUILD_PROPERTIES_COMPILER_C_ELF_FLAGS))
 	properties.Set(constants.BUILD_PROPERTIES_COMPILER_WARNING_FLAGS, properties.Get(constants.BUILD_PROPERTIES_COMPILER_WARNING_FLAGS+"."+ctx.WarningsLevel))
 	properties.Set(constants.BUILD_PROPERTIES_ARCHIVE_FILE, coreDotARelPath.String())
 	properties.Set(constants.BUILD_PROPERTIES_ARCHIVE_FILE_PATH, coreArchiveFilePath.String())
@@ -76,10 +74,3 @@ func link(ctx *types.Context, objectFiles paths.PathList, coreDotARelPath *paths
 func wrapWithDoubleQuotes(value string) string {
 	return "\"" + value + "\""
 }
-
-func addRelaxTrickIfATMEGA2560(buildProperties *properties.Map) string {
-	if buildProperties.Get(constants.BUILD_PROPERTIES_BUILD_MCU) == "atmega2560" {
-		return ",--relax"
-	}
-	return constants.EMPTY_STRING
-}