[ELF] Fix assertion in cdsort (#71708)

It seems that some functions (.text.unlikely.xxx) may have zero size,
which
makes some builds with enabled assertions fail. Removing the assertion
and
extending one test to fix the build.
The sorting can process such zero-sized functions so no changes there
are needed

Author: spupyrev

lld/ELF/CallGraphSort.cpp

@@ -287,7 +287,6 @@ DenseMap<const InputSectionBase *, int> elf::computeCacheDirectedSortOrder() {
     if (res.second) {
       // inSec does not appear before in the graph.
       sections.push_back(inSec);
-      assert(inSec->getSize() > 0 && "found a function with zero size");
       funcSizes.push_back(inSec->getSize());
       funcCounts.push_back(0);
     }

lld/test/ELF/cgprofile-txt2.s

@@ -5,11 +5,13 @@
 # RUN: echo "B C 50" >> %t.call_graph
 # RUN: echo "C D 40" >> %t.call_graph
 # RUN: echo "D B 10" >> %t.call_graph
+# RUN: echo "D E 1" >> %t.call_graph
 # RUN: ld.lld -e A %t --call-graph-ordering-file %t.call_graph --call-graph-profile-sort=hfsort -o %t2
 # RUN: llvm-readobj --symbols %t2 | FileCheck %s --check-prefix=CHECKC3
 # RUN: ld.lld -e A %t --call-graph-ordering-file %t.call_graph --call-graph-profile-sort=cdsort -o %t2
 # RUN: llvm-readobj --symbols %t2 | FileCheck %s --check-prefix=CHECKCDS
 
+## The expected order is [B, C, D, E, A]
 # CHECKC3:      Name: A
 # CHECKC3-NEXT: Value: 0x201123
 # CHECKC3:      Name: B
@@ -18,7 +20,10 @@
 # CHECKC3-NEXT: Value: 0x201121
 # CHECKC3:      Name: D
 # CHECKC3-NEXT: Value: 0x201122
+# CHECKC3:      Name: E
+# CHECKC3-NEXT: Value: 0x201123
 
+## The expected order is [A, B, C, D, E]
 # CHECKCDS:      Name: A
 # CHECKCDS-NEXT: Value: 0x201120
 # CHECKCDS:      Name: B
@@ -27,6 +32,8 @@
 # CHECKCDS-NEXT: Value: 0x201122
 # CHECKCDS:      Name: D
 # CHECKCDS-NEXT: Value: 0x201123
+# CHECKCDS:      Name: E
+# CHECKCDS-NEXT: Value: 0x201124
 
 .section    .text.A,"ax",@progbits
 .globl  A
@@ -47,3 +54,7 @@ C:
 .globl  D
 D:
  nop
+
+.section    .text.E,"ax",@progbits
+.globl  E
+E: