tests: use max-llvm-major-version instead of ignore-llvm-version range like N - 99

For tests that use `ignore-llvm-version: N - M`, replace that with
`max-llvm-major-version: N-1`.

tests/assembly/riscv-soft-abi-with-float-features.rs

@@ -2,7 +2,7 @@
 //@ compile-flags: --target riscv64imac-unknown-none-elf -Ctarget-feature=+f,+d
 //@ needs-llvm-components: riscv
 //@ revisions: LLVM-PRE-20 LLVM-POST-20
-//@ [LLVM-PRE-20] ignore-llvm-version: 20 - 99
+//@ [LLVM-PRE-20] max-llvm-major-version: 19
 //@ [LLVM-POST-20] min-llvm-version: 20
 
 #![feature(no_core, lang_items, f16)]

tests/assembly/x86_64-cmp.rs

@@ -1,7 +1,7 @@
 //@ revisions: DEBUG LLVM-PRE-20-OPTIM LLVM-20-OPTIM
 //@ [DEBUG] compile-flags: -C opt-level=0
 //@ [LLVM-PRE-20-OPTIM] compile-flags: -C opt-level=3
-//@ [LLVM-PRE-20-OPTIM] ignore-llvm-version: 20 - 99
+//@ [LLVM-PRE-20-OPTIM] max-llvm-major-version: 19
 //@ [LLVM-20-OPTIM] compile-flags: -C opt-level=3
 //@ [LLVM-20-OPTIM] min-llvm-version: 20
 //@ assembly-output: emit-asm

tests/codegen/branch-protection-old-llvm.rs

@@ -7,7 +7,7 @@
 //@ [LEAF] compile-flags: -Z branch-protection=pac-ret,leaf
 //@ [BKEY] compile-flags: -Z branch-protection=pac-ret,b-key
 //@ compile-flags: --target aarch64-unknown-linux-gnu
-//@ ignore-llvm-version: 19 - 99
+//@ max-llvm-major-version: 18
 
 #![crate_type = "lib"]
 #![feature(no_core, lang_items)]

tests/codegen/call-metadata.rs

@@ -2,7 +2,7 @@
 // scalar value.
 
 //@ compile-flags: -O -C no-prepopulate-passes
-//@ ignore-llvm-version: 19 - 99
+//@ max-llvm-major-version: 18
 
 #![crate_type = "lib"]
 

tests/codegen/integer-cmp.rs

@@ -3,7 +3,7 @@
 
 //@ revisions: llvm-pre-20 llvm-20
 //@ [llvm-20] min-llvm-version: 20
-//@ [llvm-pre-20] ignore-llvm-version: 20 - 99
+//@ [llvm-pre-20] max-llvm-major-version: 19
 //@ compile-flags: -C opt-level=3
 
 #![crate_type = "lib"]