llpcSpirvLowerGlobal: place allocas and their initializers more carefully
llpcSpirvLowerGlobal: place allocas and their initializers more carefully

Avoid an issue where allocas are moved out of the entry block by a later
inlining.

GPUOpen-Drivers/llpc,GPUOpen-Drivers/llpc,GPUOpen-Drivers/llpc,GPUOpen-Drivers/llpc,GPUOpen-Drivers/llpc