This changes the initialisation of output sections so that it is
possible to create read-only sections fed only from linker script
BYTE, SHORT, LONG or QUAD. That currently isn't possible even for one
of the well-known ELF sections like .rodata, because once a section is
marked read/write that sticks. On the other hand if we start
read-only, well-known ELF sections end up read/write as appropriate.
For example .tdata will still be SHF_ALLOC + SHF_WRITE + SHF_TLS.
PR 26378
* ldlang.c (map_input_to_output_sections): Start with a read-only
section for data statements.
* testsuite/ld-elf/size-2.d: Adjust to suit.
Also restore them somewhat closer to the original. They originally
failed on many targets, and a month later I "simplified" them as part
of a larger patch fixing other failing tests. That unfortunately lost
their main purpose, which was to test TLS layout.
* testsuite/ld-elf/size-1.d,
* testsuite/ld-elf/size-1.s,
* testsuite/ld-elf/size-1.t: New test.
* testsuite/ld-elf/size-2.d,
* testsuite/ld-elf/size-2.s,
* testsuite/ld-elf/size-2.t: New test.
* testsuite/ld-scripts/size-1.d,
* testsuite/ld-scripts/size-1.s,
* testsuite/ld-scripts/size-1.t,
* testsuite/ld-scripts/size-2.s,
* testsuite/ld-scripts/size-2.d,
* testsuite/ld-scripts/size-2.t,
* testsuite/ld-scripts/size.exp: Delete.
