1. A computer implemented method for implementing run-time instrumentation indirect sampling by address, the method comprising: initializing a run-time-instrumentation control based on executing a load run-time instrumentation controls (LRIC) instruction, the LRIC instruction establishing a sampling mode and a sample-point address (SPA) control according to a sampling control block included as an operand of the LRIC instruction, the sampling mode selectable to enable an indirect sampling by address mode in combination with a directed sampling mode that triggers sampling upon execution of a next sequential instruction following a run-time instrumentation next instruction, and/or an interval-based sampling mode that triggers sampling at specified intervals; collecting into a collection buffer that is internal to a processor, a plurality of run-time instrumentation information comprising events and data associated with execution of an instruction stream while the instruction stream is executing on the processor; reading sample-point addresses from a sample-point address array in a register that is internal to the processor; comparing, by the processor, the sample-point addresses to an address associated with an instruction from the instruction stream executing on the processor; recognizing a sample point upon execution of the instruction associated with the address matching one of the sample-point addresses; and triggering a transfer of the run-time instrumentation information from the collection buffer to a run-time instrumentation program buffer as a reporting group based on recognizing the sample point, wherein the run-time instrumentation program buffer is located in memory that is external to the processor.