libroot: Disable -Werror and re-enable safeClone usage.

This code depends on the inline buffer being used at
the moment. Eventually we should refactor it, but for
now, just use the deprecated method.

Should fix regressions following ICU upgrade.

src/system/libroot/add-ons/icu/ICUCtypeData.cpp

@@ -543,17 +543,11 @@ ICUCtypeData::_GetConverterForMbState(mbstate_t* mbState,
 	if (result != B_OK)
 		return result;
 
-	UErrorCode icuStatus = U_ZERO_ERROR;
-#if U_ICU_VERSION_MAJOR_NUM < 71
 	// ... and clone it into the mbstate
+	UErrorCode icuStatus = U_ZERO_ERROR;
 	int32_t bufferSize = sizeof(mbState->data);
 	UConverter* clone
 		= ucnv_safeClone(icuConverter, mbState->data, &bufferSize, &icuStatus);
-#else
-	// ... and clone it into the mbstate
-	UConverter* clone
-		= ucnv_clone(icuConverter, &icuStatus);
-#endif
 
 	if (clone == NULL || !U_SUCCESS(icuStatus))
 		return B_ERROR;

src/system/libroot/add-ons/icu/Jamfile

@@ -8,6 +8,9 @@ UsePrivateHeaders
 	shared
 	;
 
+# needed for -Werror=deprecated-declarations
+SubDirC++Flags -Wno-error ;
+
 local architectureObject ;
 for architectureObject in [ MultiArchSubDirSetup ] {
 	on $(architectureObject) {