CDCSerial not available after PC reboot or resume from suspend

Leaving the Arduino 101 connected to the PC (as for an embedded installation), the Serial communication over USB doesn't work properly at reboot or resume from suspend state.
Both in Windows or Linux the COM or tty is shown on reboot, but it doesn't allow you to write data from PC to Arduino101 trought the Serial.

for example using the Serial Event Example:
```
/*
Serial Event example

When new serial data arrives, this sketch adds it to a String.
When a newline is received, the loop prints the string and
clears it.

A good test for this is to try it with a GPS receiver
that sends out NMEA 0183 sentences.

Created 9 May 2011
by Tom Igoe

This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/SerialEvent

*/

String inputString = ""; // a string to hold incoming data
boolean stringComplete = false; // whether the string is complete

void setup() {
// initialize serial:
Serial.begin(115200);
while (!Serial) ;
// reserve 200 bytes for the inputString:
inputString.reserve(200);
}

void loop() {
// print the string when a newline arrives:
if (stringComplete) {
Serial.println(inputString);
// clear the string:
inputString = "";
stringComplete = false;
}
}

/*
SerialEvent occurs whenever a new data comes in the
hardware serial RX. This routine is run between each
time loop() runs, so using delay inside loop can delay
response. Multiple bytes of data may be available.
*/
void serialEvent() {
while (Serial.available()) {
// get the new byte:
char inChar = (char)Serial.read();
// add it to the inputString:
inputString += inChar;
// if the incoming character is a newline, set a flag
// so the main loop can do something about it:
if ((inChar == '\n') || (inChar == 10) || (inChar == 13)) {
stringComplete = true;
}
}
}
```
At reboot or resume from suspend state the Serial communication doesn't work properly and Arduino IDE freezes while trying to write data on Serial through Serial Monitor.

Only a Master Reset resolve this issue.

No source files or tests are named. Start by reproducing the Arduino 101 USB CDC failure after reboot and resume from suspend on Windows or Linux, then trace the serial reset and reconnection path; done means the Serial Monitor can write data without freezing, without requiring a master reset.

Written by the indexing model from the issue text.