[Bazel] Use posix definitions for FreeBSD

[wamuir]

Summary

Presently, definitions default to those for Linux which are not defined for FreeBSD (HAVE_LSEEK64, HAVE_MALLINFO, etc.). Patch sets os_defines to posix definitions under FreeBSD.

[GMNGeoffrey]

Thanks :-) LGTM if pre-merge checks pass.

[wamuir]

Awesome, thanks so much

[GMNGeoffrey]

I'm guessing from your profile history that you don't have commit access? Need me to land this for you?

[wamuir]

Correct, no commit access and yes that'd be great. Thanks again

[GMNGeoffrey]

The patch doesn't have authorship information attached, could you tell me what name and email you'd like me to use for the commit? (see https://llvm.org/docs/DeveloperPolicy.html#attribution-of-changes)

[wamuir]

Sorry about that. William Muir [e-mail]

[GMNGeoffrey]

In D109913#3004909, @wamuir wrote:

Sorry about that. William Muir [e-mail]

No worries :-)

utils/bazel/llvm-project-overlay/llvm/config.bzl

win32_defines = [
     r'LLVM_PLUGIN_EXT=\".dll\"',
 ]
 
 # TODO: We should switch to platforms-based config settings to make this easier
 # to express.
 os_defines = select({
     "@bazel_tools//src/conditions:windows": win32_defines,
     "@bazel_tools//src/conditions:darwin": macos_defines,
+    "@bazel_tools//src/conditions:freebsd": posix_defines,
     "//conditions:default": linux_defines,
 })
 
 # TODO: We should split out host vs. target here.
 llvm_config_defines = os_defines + select({
     "@bazel_tools//src/conditions:windows": native_arch_defines("X86", "x86_64-pc-win32"),
     "@bazel_tools//src/conditions:darwin": native_arch_defines("X86", "x86_64-unknown-darwin"),
     "@bazel_tools//src/conditions:linux_aarch64": native_arch_defines("AArch64", "aarch64-unknown-linux-gnu"),