round shared req size to multiple of 8 bytes

Change-Id: Ia14ba57dd4e7ebe34aa2981610d3aaec450a2937
implemented busywait_shared

Change-Id: I9f7e6bbcced8e355e63a1735242fc0bf6af3c577
fixed rounding of msg_len

Change-Id: Iac4ee44f82862b75ef50459ce6c19e8100765220
updated mkSharedMemoryPortal to work with rounded msg lengths

Change-Id: I2d98443cff3161daa8fef8c75789bda13dcc8b7a
handle wrap around in mkSharedMemoryPortal

Change-Id: Ibcc79bb2c2a219cd697551d583518b9f8fc5537d