[libclc] Move log1p/asinh/acosh/atanh to the CLC library

[frasercrmck]

These four functions all related in that they share tables and helper functions. Furthermore, the acosh and atanh builtins call log1p.

As with other work in this area, these builtins are now vectorized. To enable this, there are new table accessor functions which return a vector of table values using a vector of indices. These are internally scalarized, in the absence of gather operations. Some tables which were tables of multiple entries (e.g., double2) are split into two separate "low" and "high" tables. This might affect the performance of memory operations but are hopefully mitigated by better codegen overall.

[mgorny]

This change seems to have broken the test suite:

ctest -j 32 --test-load 32
Test project /var/tmp/portage/llvm-core/libclc-21.0.0.9999/work/libclc_build
    Start 1: external-calls-tahiti-amdgcn--.bc
    Start 2: external-calls-amdgcn--amdhsa.bc
    Start 3: external-calls-tahiti-amdgcn-mesa-mesa3d.bc
1/3 Test #1: external-calls-tahiti-amdgcn--.bc .............***Failed    2.67 sec
2/3 Test #3: external-calls-tahiti-amdgcn-mesa-mesa3d.bc ...***Failed    2.79 sec
3/3 Test #2: external-calls-amdgcn--amdhsa.bc ..............***Failed    2.95 sec

0% tests passed, 3 tests failed out of 3

Total Test time (real) =   2.96 sec

The following tests FAILED:
          1 - external-calls-tahiti-amdgcn--.bc (Failed)
          2 - external-calls-amdgcn--amdhsa.bc (Failed)
          3 - external-calls-tahiti-amdgcn-mesa-mesa3d.bc (Failed)
Errors while running CTest
Output from these tests are in: /var/tmp/portage/llvm-core/libclc-21.0.0.9999/work/libclc_build/Testing/Temporary/LastTest.log
Use "--rerun-failed --output-on-failure" to re-run the failed cases verbosely.

LastTest is pretty big:

Start testing: Mar 29 12:40 UTC
----------------------------------------------------------
1/3 Testing: external-calls-tahiti-amdgcn--.bc
1/3 Test: external-calls-tahiti-amdgcn--.bc
Command: "/var/tmp/portage/llvm-core/libclc-21.0.0.9999/work/libclc/check_external_calls.sh" "/var/tmp/portage/llvm-core/libclc-21.0.0.
9999/work/libclc_build/tahiti-amdgcn--.bc" "/usr/lib/llvm/21/bin"
Directory: /var/tmp/portage/llvm-core/libclc-21.0.0.9999/work/libclc
"external-calls-tahiti-amdgcn--.bc" start time: Mar 29 12:40 UTC
Output:
----------------------------------------------------------
ERROR: 918 unresolved calls detected in /var/tmp/portage/llvm-core/libclc-21.0.0.9999/work/libclc_build/tahiti-amdgcn--.bc
  %call39.i = tail call <2 x double> @__clc_ln_tbl(i64 noundef %conv38.i) #25
  %call39.i86 = tail call <2 x double> @__clc_ln_tbl(i64 noundef %conv38.i85) #25
  %call39.i142 = tail call <2 x double> @__clc_ln_tbl(i64 noundef %conv38.i141) #25
  %call39.i257 = tail call <2 x double> @__clc_ln_tbl(i64 noundef %conv38.i256) #25
  %call39.i198 = tail call <2 x double> @__clc_ln_tbl(i64 noundef %conv38.i197) #25
  %call39.i286 = tail call <2 x double> @__clc_ln_tbl(i64 noundef %conv38.i285) #25
  %call39.i227 = tail call <2 x double> @__clc_ln_tbl(i64 noundef %conv38.i226) #25
  %call39.i171 = tail call <2 x double> @__clc_ln_tbl(i64 noundef %conv38.i170) #25
  %call39.i115 = tail call <2 x double> @__clc_ln_tbl(i64 noundef %conv38.i114) #25
[…]

LastTest.log

[frasercrmck]

Thanks for the heads up, @mgorny - we really need this tested in PRs.

I've fixed forward in #133691.