meson: Always add LLVM coroutines module.

It gets used by the gallium auxiliary draw module, which gets used
pretty much always when LLVM is used as JIT.

At the same time most builds don't hit the issue here because the
shared library of LLVM contains all modules.

Fixes: d32690b43c91 ("gallivm: add coroutine pass manager support")
Closes: https://gitlab.freedesktop.org/mesa/mesa/issues/951
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>
diff --git a/meson.build b/meson.build
index 1c14f4d..8f30a94 100644
--- a/meson.build
+++ b/meson.build
@@ -1249,7 +1249,7 @@
 endif
 
 llvm_modules = ['bitwriter', 'engine', 'mcdisassembler', 'mcjit']
-llvm_optional_modules = []
+llvm_optional_modules = ['coroutines']
 if with_amd_vk or with_gallium_radeonsi or with_gallium_r600
   llvm_modules += ['amdgpu', 'native', 'bitreader', 'ipo']
   if with_gallium_r600
@@ -1262,9 +1262,6 @@
     'lto', 'option', 'objcarcopts', 'profiledata',
   ]
 endif
-if with_gallium_opencl or with_gallium_softpipe
-  llvm_optional_modules += ['coroutines']
-endif
 
 if with_amd_vk or with_gallium_radeonsi
   _llvm_version = '>= 8.0.0'