When an OpConstantComposite result is used by multiple instructions,
declare it as a module-scope `const` instead of inlining the constant
at each use site. This fixes an issue whereby the spirv-reader was
massively inflating the size of the WGSL it produces, which was caught
via an OOM fuzzer bug.
Bug: oss-fuzz:57795
Change-Id: Iac8c6a2147a7e2ebfddbaacae9fcb1dbe0b59e9d
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/128881
Auto-Submit: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: David Neto <dneto@google.com>