[LLD][ELF] - Linkerscript: add a support for expressions for section's filling
Imagine the script:
.section: {
...
} = FILL_EXPR
LLD assumes that FILL_EXPR is a number, and does not allow
it to be an expression. Though that is allowed by specification:
https://sourceware.org/binutils/docs-2.32/ld/Output-Section-Fill.html
This patch adds a support for cases when FILL_EXPR is simple math expression.
Fixes https://bugs.llvm.org/show_bug.cgi?id=42482.
Differential revision: https://reviews.llvm.org/D64130
llvm-svn: 365143