vmlinux.lds: Fix TEXT_MAIN to include .text.start and friends

vmlinux.lds: Fix TEXT_MAIN to include .text.start and friends

Since:

  6568f14cb5ae ("vmlinux.lds: Exclude .text.startup and .text.exit from TEXT_MAIN")

the TEXT_MAIN macro uses a series of patterns to prevent the
.text.startup[.*] and .text.exit[.*] sections from getting
linked into the vmlinux runtime .text.

That commit is a tad too aggressive: it also inadvertently filters out
valid runtime text sections like .text.start and
.text.start.constprop.0, which can be generated for a function named
start() when -ffunction-sections is enabled.

As a result, those sections become orphans when building with
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION for arm:

  arm-linux-gnueabi-ld: warning: orphan section `.text.start.constprop.0' from `drivers/usb/host/sl811-hcd.o' being placed in section `.text.start.constprop.0'
  arm-linux-gnueabi-ld: warning: orphan section `.text.start.constprop.0' from `drivers/media/dvb-frontends/drxk_hard.o' being placed in section `.text.start.constprop.0'
  arm-linux-gnueabi-ld: warning: orphan section `.text.start' from `drivers/media/dvb-frontends/stv0910.o' being placed in section `.text.start'
  arm-linux-gnueabi-ld: warning: orphan section `.text.start.constprop.0' from `drivers/media/pci/ddbridge/ddbridge-sx8.o' being placed in section `.text.start.constprop.0'

Fix that by explicitly adding the partial "substring" sections (.text.s,
.text.st, .text.sta, etc) and their cloned derivatives.

While this unfortunately means that TEXT_MAIN continues to grow,
these changes are ultimately necessary for proper support of
-ffunction-sections.

Fixes: 6568f14cb5ae ("vmlinux.lds: Exclude .text.startup and .text.exit from TEXT_MAIN")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: live-patching@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://patch.msgid.link/cd588144e63df901a656b06b566855019c4a931d.1762991150.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/oe-kbuild-all/202511040812.DFGedJiy-lkp@intel.com/