Merge branch 'releases/gcc-10' into devel/omp/gcc-10

Merged up to e09d626551fef9b5719073427170d11e97038c44 (Jun 14, 2020)

diff --cc gcc/cp/cp-gimplify.c
Simple merge

diff --cc gcc/cp/decl.c
Simple merge

diff --cc gcc/cp/parser.c
Simple merge

diff --cc gcc/cp/pt.c
Simple merge