Bug#1078780: mesa: Disable llvmpipe on loong64

Subject: mesa: Disable llvmpipe on loong64 Source: mesa Severity: normal Dear Maintainer, The loongarch architecture of llvm does not support mcjit, so don't use llvmpipe in loongarch at this time. wuruilong -- System Information: Debian Release: trixie/sid   APT prefers unreleased

Bug#1078780: (no subject)

Subject: mesa: Disable llvmpipe on loong64 Source: mesa Severity: normal Dear Maintainer, For the record as a draft, please don't merge the patches yet! wuruilong