This arranges for SIAR and SDAR to be set when a trace interrupt
is triggered by a non-zero setting of the MSR[TE] field. According to
the ISA, SIAR should be set to the address of the instruction and SDAR
should be set to the effective address of its storage operand if any.
This also fixes setting of SDAR by the PMU when an alert occurs;
previously it was always just set to zero.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>