Manpages of src:gcc10

• cpp-10(1)
• g++-10(1)
• gcc-10(1)
• gccgo-10(1)
• gcov-10(1)
• gcov-dump-10(1)
• gcov-tool-10(1)
• gdc-10(1)
• gfortran-10(1)
• go-10(1)
• gofmt-10(1)
• lto-dump-10(1)