[PR124572, LRA]: Deal with generation of reload insns during elimination

It was assumed that elimination in LRA does not generate new reload
insns.  In the testcase the elimination of SFP subreg generates reload
insn of the subreg and this insn is added at end of RTL code.  The insn
is also skipped for necessary processing.  This results in ICE.  The patch
checks creation of reloads insn during elimination, insert them in the right
place, and add them for later processing.

gcc/ChangeLog:

	PR rtl-optimization/124572
	* lra-eliminations.cc (lra_eliminate): Push new reload insns for
	eliminations in insns.

gcc/testsuite/ChangeLog:

	PR rtl-optimization/124572
	* gcc.target/aarch64/pr124572.c: New.